Not a definitive answer but I'm about to test my TT Raptor Titan 50 / Spirit RS setup with Spirit governor and hall sensor, but at present I just have one magnet on the fan/flywheel. I tested the sensor in spirit settings (RPM sensor tester) and the indicator goes on/off when I spin the motor on the bench. Haven't started the motor yet so maybe I'll have a similar issue if the governor won't hold at lower rpms. I'm looking for 1500/1600/1700 as a start. I do have another fan/flywheel with 2 magnets so will substitute that if needed, and set the 'sensing divider' to 2. By the way I'm not planning to use a separate channel for Governor, just using Flight Modes / flat throttle curves and letting the FBL governor do its control as-per an ESC setup. Have I missed something here?
I'll be interested to find out how you progress. This is a 'new' (old but came to me un-started) Raptor 50 kit which I've nearly finished. I used to fly a Raptor50 years ago so it's interesting to see how the Spirit RS will work in 'flybar' mode. I have another question regarding the setup of "6 degree tuning" for the flybar head but will start a new thread.....
Cheers, Andy