Herelink on Hybrid

I have been thrown a hospital pass and could do with a medic, please.
Hybrid drone with a hex-Y config on a pixhawk 2.1 cube and power management to take 2000w generator power and invert to DC. All works fine on the stock RC supplied which is a 16ch. Client has desire to have RC / Telem and Video beyond 5km, first choice is Herelink to go with Cube Black.
Specific issues I had was calibrating Esc, this took me 3 days with the Herelink, figured out that powering airlink separately.
Issue now is, sticks in does not arm. No. Biggey as I use button on screen to arm, would be nice to fix. Second issue, mapping buttons to do servo function. The PMU has a signal wire that is put in to main out 7, tried configuring it to RC pass through and mapped buttons C short, D short and D long to manage the servo on the motor to switch motor FROM OFF, IDLE AND WORK But no Joy. Any help please