I don't really have an answer for you not knowing just how your "Banjo" bolts secures the gear. All I can think is that the bolt is not square to the surface it is tightening up to which is causing the movement. You might have to inspect that closely to see if there is some way to make sure it is square to the surface before tightening.
The bolt in question is the one on the 127/120 gear that holds it to the groove in the Banjo. The two Satelite gears are fixed to the output of the spindle gearbox and the input to the quick change gearbox. So it's only the gear on the banjo that either requires some kind of magic methodology or learns to live a bit of a sloppy life. I was hoping for some magic methodology but failing that, sloppy living it will be.