VTOL tailsitter, transfer full authority from FCS to Rotors

VTOL Tailsitter, SITL

What I want to do is to limit/ or pin flight control surfaces, and transfer full authority to the four rotors during hover and forward modes / quad and plane modes in order to test a controller. I’m not entirely sure on what to modify,
My strategy is to:
i) For a start, maybe I can pin/limit the elevons in the mixer file by
O: 10000 10000 0 0 0
assigning Z: to channels 1,2,3

ii) Then modify vtol_att_control

Any input would be appreciated