Help tuning 14" quad

Appreciate your answer.
I can’t quantify the effectiveness, but we tried tuning the quad again, without any visible difference in flight. We also looked in the logs (desired vs. measured angles and rates, vibrations) and the FFT analyzing tool to look for differences and improvements.

Can you refer me \ let me know what to look for in ‘post processing’ log data from IMU?
First which logging options should be enabled exactly as I’ve only seen post filtering.
Second is how and what should I learn from looking at that data.
I promise that I’m looking at the documentation, quite often. But it can be overwhelming and complex with all the cross references, especially for someone new to ArduPilot.
Currently:
INS_LOG_BAT_MASK = 7 - all 3 IMU are logged
INS_LOG_BAT_OPT = 2 - only post-filtering log is enabled. Do you mean we should log both pre- and post-filtering? What about the logging at sensor rate? (BAT_OPT bit 1).


One thing I noticed is that during hover, the throttle value (I don’t know which measurement unit it is) was around 0.15, while MOT_THST_HOVER is set to 0.2.
Plus, MOT_SPIN_MIN = 17, MOT_SPIN_ARM = 14.
I read this post which had low frequency vibrations, and it made me check our values.
My point is that if these three parameters are on the same scale - it doesn’t make sense to leave them as is, for the reasons explained in the linked post.

P.S I also noticed that MOT_HOVER_LEARN is set to 2… should it make a difference.