I think the problem here is, that if you have your joystik outside the “neutral” position and press the “force trim” button it might store that position, but if you release your stick afterwards you’re immediately moving away from the desired setting - so the question is, how a force trim will be working with a spring joystick and when/how will it store the setting relative to “neutral”. Maybe the increase/decrease trim buttons are the only way to go as you can set them out of the neutral position respectively adjustig them until you can release to the neutral position.