I am tracking this issue: https://github.com/betaflight/betaflight/issues/5516

I can't wait to see how a STM32H7 will perform on a quadcopter, and what it will allow for :)

Betaflight is oriented towards racing drones, there are a whole slew of open source autopilot firwares available.

PX4

Ardupilot

Cleanflight

iNav

etc

Each is oriented towards different types of audiences based on features and license.