Hi Richard,
@zeppehpt1 thanks for contributing this. And well done on submitting your thesis! The thing is we already have a haphazard area filtering process here:

Your function would need to be integrated within this function for it to be cohesively integrated within the current set up.

What really needs fixing is this step:

I think it would be better to skip non-closed polygons in that function. But I didn't implement it before because it seemed to give some unexpected outputs. But I was in a rush and wasn't sure whether I'd overlooked something. We should check that again. Skipping those cases would be the quickest and cleanest way to proceed. Would you be willing to check that on your pipeline (I can send you and edited branch)?

Thank you very much!

Oh yes, I must have overlooked that. But it seems that the step you mentioned might be the reason, because with my pipeline the additional cleaning step was always necessary even though I was using the latest version of the package.

Yes, I'm willing to look into it and hope I can help!