I have a Truvative shiftguide that I want to use running 2×9 and bash on my Inbred 456. I get that I need to remove a driveside spacer. My question to the more knowledgeable is this – Chainguide against the BB/spacer/bearing? or Spacer against BB/chainguide/bearing? 😕 Feel free to ridicule me over my lack of know-how 🙂

you probably don't even need to fit that hideous thing, shorten your chain, set-up your mech and chainline properly and I doubt you'll drop your chain very often and when you do it'll only be to the granny ring anyway.

Frame-chainguide-spacer-bearing is the most likely from a fitment point of view. If it works better with the spacer between the frame and the chainguide, then do that.