Changing a TileSet while project is running breaks Area2D collision

[Hex4F]

Godot version:
3.2.3

OS/device including version:
Windows 7

Issue description:
Rapidly calling TileSet.tile_set_region seems like a convenient way to handle animated tiles, but doing so causes Area2D collisions with TileMaps using that TileSet to become strange and inconsistent. This isn't an issue specific to setting the tile's region or collision: even more innocuous changes such as cycling the color with tile_set_modulate will cause it. After stopping the repeated calls, the problem immediately goes away.

Are TileSets not intended to be changed so quickly? I couldn't find any mention of this. I hope not, because it's a simple and convenient way to implement a bunch of different tile effects. AnimatedTextures are very rigid in contrast (and caused irreproducible bugs for someone I'm working with).

Steps to reproduce:
Repeatedly change a TileMap's TileSet while an Area2D is colliding with it.

Minimal reproduction project:
ExitedEntered.zip

[Calinou]

Rapidly calling TileSet.tile_set_region seems like a convenient way to handle animated tiles,

This is a bad way to do it performance-wise. Look into using a shader instead.

[Hex4F]

This is a bad way to do it performance-wise. Look into using a shader instead.

Done. Thanks for the fast response.

I'm curious as to why that is, though. Does changing a TileSet force some kind of cache to be rebuilt? I didn't realize moving the region would be more expensive than sending a UV offset (or indexed table of them) to the tiles' shader materials.