Just signed up as was trying to figure the "HardwareTimer.h" library with respect to setting the PWM duty cycle.
Found the answer; use setCaptureCompare in a thread and, wow what a great forum.
Been doing ucontrollers for some time now mainly PIC24 DsP.
Tried an UNO and Arduino IDE a while back and far less complex to get quick project up an running.
Grabbed a few NANO's and now i am hooked

So though i would up the anti and try a WeAct Black Pill STM32F411CE of ebay and very happy with the performance.
Coupled with the new Arduino IDE ver TWO beta 11 and think we are well on the way to being an Arduino STM32 convert

Though I would say hello imk