There is a discussion going on elsewhere on lateral balance.
I have noticed no trim changes in any of my multi engine planes as fuel is used unevenly during a flight and the laterally balance is changing constantly as my engines use fuel at slightly different rates.I include the duellist,Stafford b-24,twin stick,c-160,twin Comanche.even minor variations in rpm at different throttle setting have not caused trim changes,any one notice their trim changing as your flight progresses?