I was thinking about this. Does the latch need to be perfectly centered? Or does it just need to cover the ball so that it is contained?
This is something that would be worth testing once people start shooting 10+ shot groups to see the effect of centered vs. intentionally not centered.
I haven't tested it but here are my anecdotal thoughts/experience. I started shooting prb with pre-cut patches. I logged 2,000+ shots a year for a series of years. The first several were with pre-cut patches. At some point I switched to cutting them at the muzzle. I never saw any significant change in the scores I was shooting that could be attributed to the change.
For me this switch was out of convenience. I could keep a bolt of material on hand and when it was time to go to a shoot all I had to do was cut off how much I needed and put it in my shooting box or bag. No time spent pre punching patches and no need to inventory different sizes for different calibers.
Another nice biproduct of switching is I no longer had strangers coming up to me while I was in the middle of shooting a match to tell me I would never be able to shoot competitively with pre-cut patches. Every time these conversations happened, I would ask the person if they had ever tested this or had anything quantifiable to prove this, such as a difference in scores. I would always try to figure out their grounds for this belief. The response was always to repeat their opinion or make an appeal to authority.
The theory of the anti pre-cut camp is that you are not getting the ball perfectly centered in the patch like you are when you cut them at the muzzle. They think the lack of concentricity of the ball in the patch effects accuracy. I have never gotten an explanation of what they think is physically causing said effect.
My theory is that as long as the patch has full contact around the circumference of the ball, it will do its job. When I was shooting pre-cut I would try to keep the ball reasonably centered in the patch but not to the point of getting OCD about it. With the right sized patches, you have some wiggle room.
I think if a nonconcentric patch is effecting the balls flight as it exits the barrel, it would only be in extreme cases. Basically unless you are to the point where you feel like the ball is going to slip off one side of the patch when you start it or you have a super long tail sticking up on one side when you are starting it I would say it is fine. If lack of concentricity had an effect, I also suspect it would be magnified with a higher pressure load or loose loading ball/patch combinations.