Originally Posted by bikingshearer

Unless I'm misunderstanding you, that won't work. All it will do is move the NDS lockring a few mm to the left and add a couple of grams of weight. It will do nothing about moving either cup, DS or NDS, and hence will not do anything about repositioning the spindle. The fixed cup can only go so far in. You can move it outward some with spacers, but the BB shell is kind of a hard stop for moving it inbound. (Not true with Phil Wood BBs and some others that don't have a lip on the DS cup, but you aren't dealing with those.)

Good luck. Trying to figure out what BB dimension to use has always been a (frustrating) challenge for me. Here's hoping you nail it the first time.