Bootstrap is a term I don’t quite understand, but I can share my start-up sequence and PWM code for 1634 with you. I’ll see if I can find my old 841 code somewhere too.
Yep. I’ve actually designed a driver that uses all of those pins. I just haven’t got around to building it yet (one of those projects standing in line). It’s a slightly more advanced version of these: Driver giveaway: Constant current 17mm drivers, winners (finally) announced, post #2.