On APs with Yaw coordination, using the roll trim may cause problems too. Generally they allow small roll displacements using stick force (say up to 4 degrees), but maintain heading, and larger roll angles result in a coordinated turn. If you simply use roll trim it will still try to maintain heading and you'll end up out of balance, which is a good start to getting the 'leans', and will require additional input (pedals) which rather defeats the object.
If you use the trim release button you will also have cancelled the pitch trim datum too. I personally was taught not to trim into turns. I was also taught (at the FW stage) the importance of having the a/c accurately trimmed and have found these maxims have stood me in good stead for the IFR stuff I done. The whole philosophy of flying IF should be to reduce your flying workload as far as possible.