My QB fuse had the correct 'starting hole' rivet missing, as it was supposed to be. I looked at many flying planes before I cut these holes to get a feel for size/location, and took pictures. Those fly-in breakfasts are handy for these types of "inspections." I found all kinds of different sized holes for the flap rods. I connected the flap motor and ran the flaps up and down, as others have stated, to ensure the holes were big enough and in the correct location to avoid any issues.
Inspect some flying RV's, if you can, to get a feel for this. It certainly helps.