So I worked on the TOP SabreFD gear diff tonight (also fits M05/M06) and found that the revised clear o-rings (PP-GDRS02) for the TOP's S4 actually fits in the outdrive sides of the gear diff housing. TOP mentioned they don't fit and was working on a fix.

ANYWAY, since they do fit, I added one shim on the leaking side, new clear revised o-rings, and GreenSlime on both sides. I only had time to do one run, but no leaks.