Matt1234,
Unless i am mistaken, i just got back in the sim since a few months out, shortly after helicopters were introduced in the Sim. Back then, the Force Trim was not working, on contrairy as i brought up on the bug section of the MSFS forum after checking with a few people, when binding the Force Trim button, instead of doing a ForceTrim behaviour as we expected it, it was acting as a reset trim button.
So the setting i had since then, seems to still work on all choppers, not only CW, is trimming incremental like trimming some aicrafts, not sure if the proper way to do it, but works for me, so:
Nose Up:
Increase Rotor Longitudinal Trim
Nose Down:
Decrease Rotor Longitudinal Trim
Trim Right:
Increase Rotor Lateral Trim
Trim Left:
Increase Rotor Lateral Trim
Reset Trim:
Set Rotor Longitudinal Trim + Set Rotor Lateral Trim
In other words, when you were binding to the Set ones, it was acting as a resetting trim.
This is a MSFS thing, not CW choppers only. Seems they changed if i am not mistaken, as before i am pretty sure i binded this to Force Trim and seems it it changes to both Set Rotor now as Force Trim seems not to be part of the controls anymore from what i see when doing a Name Search.
To test out, you can play on the ground in external view and look at the Trim gauge.