I'd put a bigsby on a PRS some time back ( http://www.thefretboard.co.uk/discussion/148279/bigsby-on-wraparound-prs-too-late#latest
) however I've still been having tuning issues typical with bigsbys.
I've heavily lubricated the slots with graphite grease but the wounds strings never really slip through properly. With that in mind, just like most trem systems, having the breakpoints move instead is the most logical outcome, especially after having read many times how stable the aluminium bigsby "rocker" bridges are.
So with that in mind I first tested lubricating the bridge heavily on the stud contact points. This confirmed that there was more tuning stability with the bridge moving with the strings than having the strings slide over a locked bridge. With this confired lets go all the way.
Rounding the contact points:
Halfway, thinned the edges too so they'd not hit the studs when tilting.
Sanded and polished
While I was at it I also deepened the middle slots and flattened the top bridge radius, removed the sharp edge at the G/D transition and polished the whole thing up from scratch
Happily the final result does work better. It's more stable than a vintage strat trem with the ability to do smooth up and down bends to nearly a full tone.
Not cosmetically perfect (I'd move the peak of the curvature nearer the breakpoints in future so it sits more square)
but works well. Next is a tuneomatic on my gibson that I'm going to mod with rounded edges where they meet the height adjustment screws.