Approximately 1/2 of your point on distance is the most difficult distance to use when gap aiming, because that is where the arc of the arrow is at its highest point, and thus where the gaps are greatest. There are different ways to tackle this problem, some of which have already been mentioned.
Adjusting your arrow weight and length to reduce your point on is appealing for short distances, but if you want to use the same bow for longer distances, you'll probably need a different set of arrows.
Finding a higher anchor point on your face and using the 3 under grip also works, but too high an anchor point conflicts with good form, and you may end up not shooting as well overall.
The best thing I have found that avoids these compromises is to gap off something other than the arrow point. The top of the standard strike plate that comes with most new bows is about 1” higher than the top of the arrow. This is perfect for me to use for aiming point on at 20 yards. I also use this when hunting, where most of my shots are in the 15-20 yard range. At 15 yards, I just hold the top of the strike plate a couple of inches below the spot I want to hit. You have to get used to holding the top of the strike plate a little to the right of the spot you want to hit, but this becomes second nature after a little practice. Your right/left accuracy is still determined by the shaft of the arrow in your peripheral vision, which is always pointed at the spot you want to hit. You just ignore the point of the arrow for purposes of determining elevation.
In addition to the strike plate, there may be other features of the riser you can use to determine elevation. For longer shots where the arrow point is higher than the point you want to hit, you may be able to gap off the shelf, for example.
All of these techniques may or may not be legal depending on the rules of the particular tournament. There are no trad tournaments I’m aware of where it would be legal to mark your bow artificially or string walk. Some tournaments get picky if you change anchors. Most tournaments require that at least one finger be in contact with the arrow, so you couldn't use a fixed crawl in those tournaments. Some tournaments at the higher levels require you to eliminate everything on your bow that could be used for sighting, including the strike plate that came with the bow if it extends higher than needed to cushion the arrow. If there is some feature of your riser that can't be easily changed or covered over, then you just have to use some other bow.