No, it doesn't matter except that it DOES matter. Yes, it only matters what happens at the point of contact; however, everything done before and after contact is what determines the consistency of what happens at contact.
It will be different things for different people that gives them the best consistency of stroke, but there are certain things that are almost always necessary.
Acceleration at point of contact is one of them. If you're decelerating at point of contact, the balls just aren't going to react predictably.
If you're bridging at the cue's pivot point, you can get away with all sorts of crap, some of which was actually taught as what to do in the past. One of those things is swiping. swiping left or right while stroking for side spin. It's DEFINITELY not what you want to do to have the most consistent shooting, but it can work.
If you want to get into the weeds of it, just let me know. I can talk about this stuff for hours.