For anything where repeatability matters, I’d look closely at the gear ratio, speed, and how consistent the stroke movement is. I had a similar issue with a wobble once, and it turned out the cheap actuator just had way too much internal play. When I switched to a better dc linear actuators unit from https://www.progressiveautomations.com/collections/linear-actuators, the difference was noticeable right away—much smoother travel and no drifting. Also, think about feedback options like potentiometers or Hall sensors if you want tighter control.