"He who marches out of step hears another drum." ~ Ken Kesey
If I understand you right, it should not hinder in any way. That's near an 8th inch. That's pretty big, but I suspect that leaves near 70% in good contact. As long as there is good contact in all three points, it should be as good as any flat one.As you can imagine, it's not the flatness of the tri-loc that makes or breaks registration. Maybe something like a warped or bent screen in the extreme might introduce an issue, but I don't see this being a problem.