I also wish for good smoothing groups.
You can export the smoothed polygons, but they don’t show up as smoothing groups in Unreal Engine 5 and the smoothed faces are wrong, so I have to adjust them manually in Unreal Engine.
In other programs I then have no other choice (if I want to save the 1-3 minutes to export, import, export) but to use the flatshading.
Here’s what it looks like when I export it with “Export base normals false”.
There are no errors here, but it doesn’t look very nice either. When I activate it, it looks like this
Things look much worse in the software at my work.
But there the flatshading also looks awful but better than these errors. and to fix it in UE5 I go into the model editing mode and recalculate the normals (certainly also works in Blender, but it is always additional time necessary, privately this is no problem but at work it adds up).
Model cleanup and topology checking did not help. I am writing in the hope that you will implement something like this in RC. That would be enormously helpful! And maybe the tip with Unreal Engine will help someone.