Specifically relating to autothrottle, one of our testers has found a small tweak to their quadrant which results in a much more pleasant flying experience.
Their idle throttle detent was very close to the reverse detent, and with a bit of power it changed over to reverse in idle.
Our tester rebound the detents, further apart, so now if they idle gently it stays in idle and doesn't automatically hit the reverse detent for that split second, providing a more gentle experience, with no ECAM warning.
The TCA has a resting position within idle but if you put any pressure on that resting position, the quadrant takes that as a push to the reverse detent, taking the quadrant even lower than the resting position.
An additional point of support would be to modify the null zone percentages within the Fenix MCDU. Take a moment to adjust them to your liking, and don't forget to move the reverse idle slightly further back than you normally would. If you're struggling to find the correct nullzone, try 0.5%.