I’ve got a working prototype; the lesson I’ve learned is that the Join node destroys vertex groups, no matter what.
This needs to be cleaned up before it’s usable, but it’s a start towards a non-destructive Bevel After Boolean workflow.
Bevel After Boolean Separate Objects.blend (116.2 KB)
Edit: Cleaned up the node group and modified it to not introduce extra objects!
filletAndBevel_cleaned2.blend (171.8 KB)