So, I'm working through an issue that came in the mailing list. Basically tearing in 12.5 gives out lots of single polys unlike 12.1 and I'm trying to address it in a sop solver that finds points with less than 3 edges and tries to connect them to the closets points in the mesh (within a range of distances).
It partially works in this example file, but not es beautiful as I'd like. So I'm sharing the file in case someone else has a better idea or can improve upon it.

Cheers