Yes, this is all related to this whole conversion process.
If Revit rejects the BREPs from Rhino, then we move to use SAT transfer which is slower because it moves thru actual temp files.
I expect the reason the BIM360 is so much slower is the Temp files are being pushed all the way into the BOM360 store. They probably should be in a local temp directory. Kike will need to look at this.
We continue to try and avoid the SAT process because of the speed. This takes time as we improve moving geometry transfer into Revit.