Autotune; why does larger copters not twitch, unless I move a stick?

You have a 26 Hz 2 degree oscillation and a ~1.8 Hz 10 degree oscillation, that is extremely large.

it appears to get worse over time.

There are massive outputs to the motor mixers and the yaw output seems to suddenly start and stop being noisy. The roll noise is dominating the outputs to the motors.

Most of this 26Hz noise is coming in directly through your rate measurements.

When your motor outputs look like this you can only be great full you did not crash. There is nothing here for Autotune to work with.

You have a very serisous mechanical issue you need to address here. There is nothing we can do in the flight controller to deal with this. Something is loose. It is not accel vibrations but instead it is rate vibrations that are causing the problems.

Sorry I can’t offer more insight into this without actually looking over the air frame.