I have flashed a 150hz STAR firmware w/ ontime memory and no LVP onto an ATiny13A and successfully operated the driver.
Clearly the PWM is no good. I will increase the frequency and see what happens - later.
In another thread (post #58) I posted an ‘adapter’ for placing an ATtiny13A where a PIC12F683 goes. The link in post #58 is an update to the seriously dumb mistake I made in the one from post #47/#50. It is still untested, but I have a few on the way. As I mention over there, it requires a little filing to get working. The PCB is 1.6mm thick, so it won’t really increase the size of the driver much and should really clean up the install.