The top end of your target range for your spindle length is only 3.5 mm from the length of the spindle you have. I am wondering if you cheat a bit and add a 4mm spacer between the locking cup on the NDS and bottom bracket shell. This would shift the spindle to the left a bit, but then your drive side BB cup would need to be long enough/have enough threads to put enough preload on the bearings AND give the lock ring enough threads outside the BB shell to work properly. You could dry fit this even without a spacer by threading in the fixed cup but leaving it backed out 4 mm, then install the rest of the BB to see if this would work.

To be clear, I haven't tried this before. Just brainstorming an option. Someone with personal experience might chime in here and offer up first hand experience on if this is a good idea or not.