Help in analysis of logs after crashing(autotuning)

Hi guys,we were working on arducopter 4.0.5 quadcopter in X configuration ,20 kg ,actually a hybrid one (battery n engine).we have succeeded on our first flight test(but with heavy vibrations mainly in z directions and roll pitch and yaw delays ).After which we reviewed the logs and found these vibration issues ,On Auto analysing we have found motor imbalance just an warning.We have fine tuned and gone for the second flight.But the second flight just showed a more severe vibration on its first takeoff ,but later in the second one it was much more stabilized.We initialized settings for autotuning and then put the drone in autotuning mode .All went fine at the beginning the auto twitching was done by flight a few times ,but it went away sometimes when the pilot brought back the drone.And then one motor went off and the drone took a 180 degree flip and fell down.Please help in finding the reason for crash and also help us to fix the errors.sharing the link for logs below. text

It looks like the motion reaction did not respond in time.
The autotune mode frequently and rapidly changes attitude, causing unstable motion.
We usually don’t recommend people doing autotune on big vehicles, or at least make some adjustments in settings

For large copters (with props at least 13inch or 33cm diameter) set the Rate Roll and Pitch filters to 10hz, these are: ATC_RAT_RLL_FLTT , ATC_RAT_RLL_FLTD , ATC_RAT_PIT_FLTT , ATC_RAT_PIT_FLTD , (in Copter-3.4 they are ATC_RAT_RLL_FILT and ATC_RAT_PIT_FILT)