In some cases above certain throttle value accelerometer starts to read garbage rendering inertial modes unflyable:

Not sure where this effect comes from. Possible causes:

1. Electrical noise when above certain power level ESCs draw currect in spikes causing high-frequency noise.
2. Mechanical noise

In both cases I suspect resonance with MEMS accelerometer natural frequency. Datasheet doesn't specify it for accelerometers but for gyros it's in range 27-40kHz for typical gyros. If I'm correct adding mechanical damping that absorbs high-frequency vibrations and electrical filtering (adding a capacitor to power supply) will help.

In any case the resonance effect is unsafe for the craft and we should be able to detect it and act accordingly.