diff --git a/crates/fj-core/src/objects/object_set.rs b/crates/fj-core/src/objects/object_set.rs
index 9fb8f61d5..9f727f144 100644
--- a/crates/fj-core/src/objects/object_set.rs
+++ b/crates/fj-core/src/objects/object_set.rs
@@ -28,16 +28,17 @@ impl<T> ObjectSet<T> {
     /// # Panics
     ///
     /// Panics, if the iterator contains duplicate `Handle`s.
-    pub fn new(handles: impl IntoIterator<Item = Handle<T>>) -> Self
+    pub fn new<H>(handles: impl IntoIterator<Item = H>) -> Self
     where
         T: Debug + Ord,
+        H: Into<HandleWrapper<T>>,
     {
         let mut added = BTreeSet::new();
         let mut inner = Vec::new();
 
-        for handle in handles {
-            let handle = HandleWrapper::from(handle);
+        let handles = handles.into_iter().map(|handle| handle.into());
 
+        for handle in handles {
             if added.contains(&handle) {
                 panic!(
                     "Constructing `ObjectSet` with duplicate handle: {:?}",
@@ -149,13 +150,14 @@ impl<T> ObjectSet<T> {
     ///
     /// Panics, if the update results in a duplicate item.
     #[must_use]
-    pub fn replace<const N: usize>(
+    pub fn replace<H>(
         &self,
         original: &Handle<T>,
-        replacements: [Handle<T>; N],
+        replacements: impl IntoIterator<Item = H>,
     ) -> Option<Self>
     where
         T: Debug + Ord,
+        H: Into<Handle<T>>,
     {
         let mut iter = self.iter().cloned().peekable();
 
@@ -185,7 +187,7 @@ impl<T> ObjectSet<T> {
         Some(
             before
                 .into_iter()
-                .chain(replacements)
+                .chain(replacements.into_iter().map(|handle| handle.into()))
                 .chain(after)
                 .collect(),
         )
@@ -244,7 +246,12 @@ pub type ObjectSetIntoIter<T> = iter::Map<
 
 #[cfg(test)]
 mod tests {
-    use crate::{objects::Cycle, operations::insert::Insert, Core};
+    use std::collections::HashSet;
+
+    use crate::{
+        objects::Cycle, operations::insert::Insert, storage::HandleWrapper,
+        Core,
+    };
 
     use super::ObjectSet;
 
@@ -260,4 +267,38 @@ mod tests {
         // Nothing more to test. `ObjectSet` panics on duplicate objects, and it
         // shouldn't do that in this case.
     }
+
+    #[test]
+    fn deduplicate_with_hashset() {
+        let mut core = Core::new();
+
+        let bare_cycle = Cycle::new([]);
+        let cycle = bare_cycle.insert(&mut core);
+
+        let standard_set = HashSet::from([cycle.clone(), cycle.clone()]);
+
+        assert_eq!(standard_set, [cycle].into());
+    }
+
+    #[test]
+    fn object_set_from_handle_wrappers() {
+        let mut core = Core::new();
+
+        let bare_cycle = Cycle::new([]);
+        let cycle_a = HandleWrapper::from(bare_cycle.clone().insert(&mut core));
+        let cycle_b = HandleWrapper::from(bare_cycle.insert(&mut core));
+
+        let _object_set = ObjectSet::new([cycle_a, cycle_b]);
+    }
+
+    #[test]
+    fn object_set_from_deduplicated_hash_set() {
+        let mut core = Core::new();
+
+        let bare_cycle = Cycle::new([]);
+        let cycle_a = HandleWrapper::from(bare_cycle.clone().insert(&mut core));
+        let cycle_b = HandleWrapper::from(bare_cycle.insert(&mut core));
+
+        let _object_set = ObjectSet::new(HashSet::from([cycle_a, cycle_b]));
+    }
 }
diff --git a/crates/fj-core/src/operations/update/cycle.rs b/crates/fj-core/src/operations/update/cycle.rs
index 1f672a424..9d1d6353b 100644
--- a/crates/fj-core/src/operations/update/cycle.rs
+++ b/crates/fj-core/src/operations/update/cycle.rs
@@ -23,16 +23,17 @@ pub trait UpdateCycle {
     ///
     /// Panics, if the object can't be found.
     ///
-    /// Panics, if the update results in a duplicate object.
+    /// Panics, if the update results in multiple handles referencing the same object.
     #[must_use]
-    fn update_half_edge<T, const N: usize>(
+    fn update_half_edge<T, R>(
         &self,
         handle: &Handle<HalfEdge>,
-        update: impl FnOnce(&Handle<HalfEdge>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<HalfEdge>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
-        T: Insert<Inserted = Handle<HalfEdge>>;
+        T: Insert<Inserted = Handle<HalfEdge>>,
+        R: IntoIterator<Item = T>;
 }
 
 impl UpdateCycle for Cycle {
@@ -51,20 +52,21 @@ impl UpdateCycle for Cycle {
         Cycle::new(half_edges)
     }
 
-    fn update_half_edge<T, const N: usize>(
+    fn update_half_edge<T, R>(
         &self,
         handle: &Handle<HalfEdge>,
-        update: impl FnOnce(&Handle<HalfEdge>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<HalfEdge>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
         T: Insert<Inserted = Handle<HalfEdge>>,
+        R: IntoIterator<Item = T>,
     {
         let edges = self
             .half_edges()
             .replace(
                 handle,
-                update(handle, core).map(|object| {
+                update(handle, core).into_iter().map(|object| {
                     object.insert(core).derive_from(handle, core)
                 }),
             )
diff --git a/crates/fj-core/src/operations/update/region.rs b/crates/fj-core/src/operations/update/region.rs
index cc83b6daa..9f28c7e83 100644
--- a/crates/fj-core/src/operations/update/region.rs
+++ b/crates/fj-core/src/operations/update/region.rs
@@ -33,16 +33,17 @@ pub trait UpdateRegion {
     ///
     /// Panics, if the object can't be found.
     ///
-    /// Panics, if the update results in a duplicate object.
+    /// Panics, if the update results in multiple handles referencing the same object.
     #[must_use]
-    fn update_interior<T, const N: usize>(
+    fn update_interior<T, R>(
         &self,
         handle: &Handle<Cycle>,
-        update: impl FnOnce(&Handle<Cycle>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Cycle>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
-        T: Insert<Inserted = Handle<Cycle>>;
+        T: Insert<Inserted = Handle<Cycle>>,
+        R: IntoIterator<Item = T>;
 }
 
 impl UpdateRegion for Region {
@@ -73,20 +74,21 @@ impl UpdateRegion for Region {
         Region::new(self.exterior().clone(), interiors)
     }
 
-    fn update_interior<T, const N: usize>(
+    fn update_interior<T, R>(
         &self,
         handle: &Handle<Cycle>,
-        update: impl FnOnce(&Handle<Cycle>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Cycle>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
         T: Insert<Inserted = Handle<Cycle>>,
+        R: IntoIterator<Item = T>,
     {
         let interiors = self
             .interiors()
             .replace(
                 handle,
-                update(handle, core).map(|object| {
+                update(handle, core).into_iter().map(|object| {
                     object.insert(core).derive_from(handle, core)
                 }),
             )
diff --git a/crates/fj-core/src/operations/update/shell.rs b/crates/fj-core/src/operations/update/shell.rs
index 6b46c76cd..961e3b730 100644
--- a/crates/fj-core/src/operations/update/shell.rs
+++ b/crates/fj-core/src/operations/update/shell.rs
@@ -23,16 +23,17 @@ pub trait UpdateShell {
     ///
     /// Panics, if the object can't be found.
     ///
-    /// Panics, if the update results in a duplicate object.
+    /// Panics, if the update results in multiple handles referencing the same object.
     #[must_use]
-    fn update_face<T, const N: usize>(
+    fn update_face<T, R>(
         &self,
         handle: &Handle<Face>,
-        update: impl FnOnce(&Handle<Face>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Face>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
-        T: Insert<Inserted = Handle<Face>>;
+        T: Insert<Inserted = Handle<Face>>,
+        R: IntoIterator<Item = T>;
 
     /// Remove a face from the shell
     #[must_use]
@@ -53,20 +54,21 @@ impl UpdateShell for Shell {
         Shell::new(faces)
     }
 
-    fn update_face<T, const N: usize>(
+    fn update_face<T, R>(
         &self,
         handle: &Handle<Face>,
-        update: impl FnOnce(&Handle<Face>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Face>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
         T: Insert<Inserted = Handle<Face>>,
+        R: IntoIterator<Item = T>,
     {
         let faces = self
             .faces()
             .replace(
                 handle,
-                update(handle, core).map(|object| {
+                update(handle, core).into_iter().map(|object| {
                     object.insert(core).derive_from(handle, core)
                 }),
             )
diff --git a/crates/fj-core/src/operations/update/sketch.rs b/crates/fj-core/src/operations/update/sketch.rs
index 192e7da19..33a96e832 100644
--- a/crates/fj-core/src/operations/update/sketch.rs
+++ b/crates/fj-core/src/operations/update/sketch.rs
@@ -23,16 +23,17 @@ pub trait UpdateSketch {
     ///
     /// Panics, if the object can't be found.
     ///
-    /// Panics, if the update results in a duplicate object.
+    /// Panics, if the update results in multiple handles referencing the same object.
     #[must_use]
-    fn update_region<T, const N: usize>(
+    fn update_region<T, R>(
         &self,
         handle: &Handle<Region>,
-        update: impl FnOnce(&Handle<Region>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Region>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
-        T: Insert<Inserted = Handle<Region>>;
+        T: Insert<Inserted = Handle<Region>>,
+        R: IntoIterator<Item = T>;
 }
 
 impl UpdateSketch for Sketch {
@@ -49,20 +50,21 @@ impl UpdateSketch for Sketch {
         Sketch::new(regions)
     }
 
-    fn update_region<T, const N: usize>(
+    fn update_region<T, R>(
         &self,
         handle: &Handle<Region>,
-        update: impl FnOnce(&Handle<Region>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Region>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
         T: Insert<Inserted = Handle<Region>>,
+        R: IntoIterator<Item = T>,
     {
         let regions = self
             .regions()
             .replace(
                 handle,
-                update(handle, core).map(|object| {
+                update(handle, core).into_iter().map(|object| {
                     object.insert(core).derive_from(handle, core)
                 }),
             )
diff --git a/crates/fj-core/src/operations/update/solid.rs b/crates/fj-core/src/operations/update/solid.rs
index f7882a637..3d30ff513 100644
--- a/crates/fj-core/src/operations/update/solid.rs
+++ b/crates/fj-core/src/operations/update/solid.rs
@@ -23,16 +23,17 @@ pub trait UpdateSolid {
     ///
     /// Panics, if the object can't be found.
     ///
-    /// Panics, if the update results in a duplicate object.
+    /// Panics, if the update results in multiple handles referencing the same object.
     #[must_use]
-    fn update_shell<T, const N: usize>(
+    fn update_shell<T, R>(
         &self,
         handle: &Handle<Shell>,
-        update: impl FnOnce(&Handle<Shell>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Shell>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
-        T: Insert<Inserted = Handle<Shell>>;
+        T: Insert<Inserted = Handle<Shell>>,
+        R: IntoIterator<Item = T>;
 }
 
 impl UpdateSolid for Solid {
@@ -49,20 +50,21 @@ impl UpdateSolid for Solid {
         Solid::new(shells)
     }
 
-    fn update_shell<T, const N: usize>(
+    fn update_shell<T, R>(
         &self,
         handle: &Handle<Shell>,
-        update: impl FnOnce(&Handle<Shell>, &mut Core) -> [T; N],
+        update: impl FnOnce(&Handle<Shell>, &mut Core) -> R,
         core: &mut Core,
     ) -> Self
     where
         T: Insert<Inserted = Handle<Shell>>,
+        R: IntoIterator<Item = T>,
     {
         let shells = self
             .shells()
             .replace(
                 handle,
-                update(handle, core).map(|object| {
+                update(handle, core).into_iter().map(|object| {
                     object.insert(core).derive_from(handle, core)
                 }),
             )