UPDATE on the IRD Defiant Double Compact. Just got off the phone with IRD, super nice support there! The Wide is indeed for an 11 speed. The regular lists 9/10 speed but of course can accommodate anything less, duh! At least I'm learning.
I think I'll get the Sakae Randnner drops. If anyone knows whether the Sunrace SP850 Rear Derailleur Replacement Pulley will work for the BL (S), please let me know!
Thanks again