Nice ! I have the same task in my wish list. Already tested the PCA9685 (generic brand) in the arduino board and servors are working perfectly in this setup. Next step is to take a brushless motor / ESC from an airplane model that is grounded (forever as it crashed to dead) and test in the lab. It should works flawlessly. I see no reason it could fail. As a last step I will try to get it to work in the Raspberry PI with Node-RED. I am not sure this last step will be easy. I remember reading many reports of troubles with the PCA9685 libraries (but have not tested yet). Unfortunatelly I wont test to soon as I am far from my lab for a good amount of time.