The gain on the gyros is at 49 and is still in rate mode.
Are you flying it in rate mode?
Two things, the belt gears are too shallow and are known to skip when applying strong power. If it makes a noise and the tail kicks out, then it is your belt slipping. Replace the two belt gears with Align and adjust it properly. That problem will go away. As far as Align gyros goes, I don't like them or trust them myself. I've had issues with them in the past and don't want to deal with any gyro that is made by Align. Another problem may be that your gain is too low if the belt isn't your issue or your setup may be partially responsible. Did you set up the tail in rate mode? BTW, moving the ball link out further typically isn't a correct fix on the tail servo.