MATEKSYS F765 WING - Arducopter Heli ESC Initialization issues

Have this issue with the latest F765 WING board with AC Heli 4.

Going by all defaults and calibrating RC inputs and SERVO outputs for heli, I can ARM the heli and see the SERVO 8 output increase/decrease and disarm without issues. The only issue is I cannot get the ESC (an old DYNAM/DETRUM 40A) on my 450 heli to initialize with tones.

Initializing the ESC directly from receiver (PWM) is fine, but same with the F-765 Wing with AC is not happening. I should say it’s very random, once in 10 attempts it does init. But with a TURNIGY BLUE SERIER 40A ESC which is also pretty old one (auto timing, 8kHz frequency) works without any issues - soon as the FC completes the boot sequence, ESC emits the init tones.

So i’m guessing it either the timing issue, or the ESC firmware/protocols not being compatible with the F-765?
The F-765 Wing has 12 PWM outputs, with S1-S10 supporting Dshot, S11-S12 not supporting. I’m using the S8 for the ESC.

Any suggestions for compatible ESC’s with this FC? Can drone ESC’s be used for helis?