@z3dev I'm currently working with furniture models, they are all hand made. I sliced 8 models (they are available here https://github.com/gilboonet/designs/blob/master/MEUBLES/readme.md, each picture open the corresp. model into jscad) and they are clean because my scripts (slicer and unflattener) can only produce patterns for models without errors (holes, non-manifold). It's certainly my process that met an unhandled condition. To produce 2 axes imbricated crosspieces, I need to slice and then split slices that are made of multiple separated pieces because crosspiece cut need to be done for each piece. As you said it is too complex to debug. I need to simplify my process, maybe voxelization could help.
