UAVCAN support in Ardupilot Rover

Not sure what would be the right place to ask it, but what is the current state of supporting UAVCAN in Ardupilot Rover code? We are trying to configure a single motor Rover with separate throttle and steering using UAVCAN VESC, and cannot figure out how to map throttle control to correct values of Once we enable ESC in CAN_D1_UC_ESC_BM mask parameter, Ardupilot starts sending 4095 to it regardless of throttle position. Anyone knows what it could be?