Not for the faint-hearted, as you can brick your esc if you get it wrong, and you'll need to be comfortable with soldering some very small wires onto the board to burn a new bootloader in. However some very interesting firmware for BLheli32 controllers, start-up looks as smooth as silk, and as this firmware is aimed at rock crawlers and their ilk it runs great slow and loaded start-ups without stuttering. Lots of info and firmware and github.