Pixhack firmware issues

I have 3 Pixhack version 2’s.

For some reason I can not get Ardupilot running on 2 of them, The one runs fine. I tried installing Px4 stable release and am experienced a number of failures and warnings from mags not gyros either not being detected or not calibrated even after numerous calibrations that appear successful with no errors during calibration.

I then tried installing PX4 master and it seems that this worked on at least one of the remaining 2 that does not run on Ardupilot.

Question.

Is it safe to regularly fly with the Master PX4 firmware?