after the change of the STM, redo a dance, and check all, calibration during 3 days to get the best, my autoquad (hexa2)seems to fly very well. No change in the subtrim (not as the first time with the old STM), just the PID to forget the wobble.
I just checked the Hold and it run very well and very stable +- 50cm may be , no more.
But the weather was too bad to go ahead.
Be care with the calibration and dance, as said, it is the most important job to get good result.