RetiredF4:
no, it trims not for zero force, it trims to maintain or achieve an ordered load factor.
I don't agree. The whole AI's fbw system is made to maintain or achieve an ordered load factor. Not the trim sub system.
Remember: You give a sidestick input, that's the load factor you order. Now fbw computers calculate the necessary load factor. When you release your side stick (normal law), you maintain the ordered load factor.
What trim does is that it "neutralizes" long term load factor orders, so the flight control surfaces can go to neutral position.