If one wants to see the problems as they stand now?
Try to import stuff from SH4 as exported by S3D.
That's why, I believe, we don't see a mass conversion project in the works at this point in time.
Until the imports are correct? It won't happen and your stuck with the limited dat format.
A secondary issue is that each object needs to be exported one at a time with S3D.
I'll address that later.