Trying to picture the control ergonomics of placing the manual trim knob on left side wall.
My hands are busiest during take off & landing phases, left on the stick (flying) & right handling engine, prop, mixture, radios, & trim (& these are the busiest times for making trim adjustments), & what ever else…
Your proposed relocation of trim knob to left side would require a control stick hand switch (right hand moved to stick while left goes to the trim knob) during those critical phases of flight, complicating & potentially destabilizing your control inputs….
My vote is if you don’t like the knob in the center, go electric with switch either on the stick or close to the throttle.
