I you group well at 10-15 yard then you're grouping well at 20, 25 and 30 yards too (its just that the target is closer and stopping the arrows before they go out any farther).

That you cannot group well when the target is beyond your comfy range is telling me you haven't learned to focus hard yet. I can't either really. For pure instinctive shooting (no sights, concentrate, aim and shoot) you MUST be able to focus and burn a hole where you want the arrow to go.

Ever notice you can shoot much better groups when you have an all white target and a quarter coin sized target, rather than a 6" ring ? Concentration, focus - its huge factor and practice make it I think.

IMO its rare for guys to shooting truly instinctive past 20 yards unless their eyesight is unbelievabley good. You can't pick a spot that far. If you have an aiming system then yeah, I can see it working (I'm asuming you don't though) ???