This thread for that error, Ardupilot determined an IMU was not operating correctly and reset it.
Could be an anomaly or bug, or sign of a hardware issue.
Roll is tracking extremely closely to Desired Roll (and same for pitch) so I wouldn’t change any PIDs yet.
Your RC1 channel (roll, left/right) has a bit of jitter but it doesn’t look very bad. Are you sticks spring-centered?
You could try increasing RC1_DZ,20 to 30
or lower these a bit
ATC_ACCEL_P_MAX and ATC_ACCEL_R_MAX to about 70000, they dont need to be very precise.