Bed Fit Splitter
Which Blender versions and systems does it work on?
Blender 4.2 LTS and newer. Tested on Blender 4.2.9 LTS and 5.1.2 on Linux. It is plain Python on Blender's own libraries, so Windows and macOS should behave the same, but they have not been tested yet.
How do I install it?
Unzip the download, then in Blender go to Edit > Preferences > Get Extensions, open the drop-down arrow at the top right, choose Install from Disk... and pick bedfit_splitter-1.0.0.zip (do not unzip that inner zip). Then press N in the 3D viewport and open the Bed Fit tab.
My model is not watertight. Will it still work?
No. Bed Fit Splitter needs a closed (watertight) mesh and tells you what is wrong instead of guessing. Repair the mesh first, by hand or with Print Fix (a separate add-on by us), then split.