Hello again :)
I noticed that the bounding box of objects that have a restricted transformation type ("translations" or "rigid") are sometimes not computed correctly:
- if objects that have "translations" type are rotated
- if objects that have "rigid" type are scaled
Text and references are not affected.

I have created a test file that you can open in Ipe where you can observe the incorrect bounding box in different scenarios:
bbox_test.pdf