@Gary-Holmgren , oh yeah, I almost forgot about the issue of not being able to use the DSP uart ports while PX4 is running.. 🙂
To work around that, you could potentially connect M0065 board to one of the UART ports that are actually connected to CPU and access it directly from linux use /dev/ttyHSx devices
You can find the linux uart ports here : https://docs.modalai.com/voxl2-linux-user-guide/#uarts - you will need an expansion board, but even something like M0141 or M0151 will do (which is probably the simplest).
However, it sounds like maybe you are close to figuring out he pwm output via px4, so perhaps this is not needed, but you can keep it in mind.
Alex