I had some Skywalker 40A with BLHeli v11 spare from the tricopter project, so I have put them on the APM X450 quad for a trial.
The BLHeli beacon is really annoying, so I turned it off. Otherwise it is a pretty basic Multi BLHeli configuration.
The ESCs were throttle calibrated using APM's all at once procedure… but it didn't work as expected, the motors remained stopped when armed. A lot of fiddling around to find some parameter changes did not work until power was cycled. Set MOT_SPIN_ARMED=200, THR_MIN=220.
Initial tests in stable, alt hold and loiter modes have been good.