Couple of points to bear in mind here:
1. The arrow is pushing on the button for only a few milliseconds near the beginning of say a 15 millisecond power stroke
2. The lateral force exerted on the arrow shaft by the button is effectively constant. (unless you make the mistake of having a stiff spring or even worse replacing the spring with a matchstick).
Reducing centre shot results re tuning in a stiffer spring. Conventional wisdom for centre shot position is the one that results in a sensible spring pressure (350-500
GM
equivalent say). Too stiff a button and the shaft-button force becomes a variable (unforgiving) and starts to affect the bending of the arrow significantly. Too soft a button and the shaft can bottom out on the on the plunger barrel and you're back to the stiff spring problem. Centre shot has little, if anything, to do with arrow alignment.