If you need to hold pressure on the wheel got the car to track straight, your portable is alignment. Specifically, the problem is cross caster. Caster is the measurement of the angle of the steering axis in degrees from vertical. You need caster for the wheel to center itself after a turn. It also allows for camber gain while cornering but that isn’t relevant to this conversation. Cars have positive caster; shopping carts have negative caster. Cross caster is the measurement of difference between left and right wheel caster, and ideally, should be zero (under one degree is a realistic expectation). Any amount of cross caster will make the centering force uneven in one direction and will result in the driver being required to constantly apply steering pressure.
Most modern suspensions don’t allow for caster to be adjusted independently. Caster/camber is adjusted simultaneously and the aligner prefers to get camber closer to spec since it has a larger bearing on tire longevity.
Ninja edit: didn’t read the last couple posts till i made mine 