The push the engine forward is a carry over from the previous models..especially the /2 era. Easier than messing with the twin shock rear swing arm.
I tried it on a G/S exactly once...never again.
Moving the single swing arm is SO much easier. With the right tools and experience, the tranny is on the bench in 30 minutes or less.
Just did it this morning..in fact for the R100GS it's even faster since you have more room.
BMW Club of Northern California, Ambassador, BMW MOA, Vice President Vintage BMW Club