Once you put the support rails on the piston, with the bump down in one edge of the wrist pin hole, there should not be any overlap and should not have to be filed. I have installed several sets and they sell different sizes for different bore ranges.
Trial fit one on a piston and I think that you will see that it will spring out and that there will be a gap.
When you do get ready to file-fit your rings, read the instructions that are included and that will help. I haven't had to clearance any oil rings, but I set the thin rings in the bore to check that there is a gap. The accordian style spacer support is what sets your oil ring tension (standard or low). Then ends will need to butt up against each other and must not overlap, but if you were to file fit this you would go to NO-Tension oil rings.
Bill M