Ensure that also Yaw is balanced.

Remove adaptive PID tuning, try to tune for higher PID, now your values are quite low. try to use also higher power, but take care that motors do not get hot. If you find a way to support the camera better, it will improve the result (supporting camera also from top)

When the gimbal is working ok, you can add back the adaptive PID tuning if you like. (but I do not usually use it)

You must also tune the follow yaw settings to your liking and practise moving with the gimbal.

You should not need any Warp stabiliser.

When the gimbal is operated normally, on normal position, frame IMU does not make a big difference, but maybe you want to get and install also frame IMU, that will enable using the gimbal more freely.

Make sure gyro is calibrated always when using the gimbal in different temperature. If it is calibrated inside, it needs to be calibrated if operated outside and temperature is different (unless temperature calibration has been performed.)

Make sure also accelerometers are well calibrated, preferably 6 point calibrated. It is usually enough to do this only when the gimbal is installed and taken into use, but time to time if there is any problems it is good to reperform it also, and there is also temperature calibration available. Your problems are likely not because of accelerometer calibration.

For PID you should get pretty good result with the auto tuning. first set it to good stability and tune one axis at time. Hold the gimbal like normally when operating it when auto tuning, but do not move it much during the tuning.