Hi everyone,

When I receive a .3mf model and need broader compatibility in slicers / old workflows, I usually convert it to .stl first, then import and rescale/check normals.

My quick checklist:
1) Open the 3MF and verify units (mm vs inch)
2) Export to STL
3) Re-import STL and check orientation + wall thickness
4) Slice a tiny test section before full print

I made a small free converter page for this specific task:
3MF to STL converter

If anyone has a better QA checklist after conversion, happy to learn.