In my experience, if you start at a certain yardage with a certain anchor, all that means is that this yardage is within your pointing range with that anchor. You then have to find out what happens closer up and further out - i.e. where the limits of that pointing range are.
I start tuning at five yards with my top anchor, which is very high, then fine-tune at ten and 15 yards, using many arrows and noticing millimeters rather than inches on the target face. Depending on many things, arrow speed only being one of them, that will get my bow tuned to 20 yards at least. My fastest current set-up will shoot accurately out to just over 30 yards tuned that way. That's not very much compared to what others report, but it's by choice and for reasons explained further down.
When I reach the limits of that initial pointing range, I move my anchor down and get another 'range of grace', so to speak. And so on until the anchor gets too low for effective pointing (remember I'm using the arrow as the sighting device, not the bow-arm).
Now, if you were set on using a certain anchor at, say, 20 to 35 yards, it would make sense to start tuning somewhere in between. Then check out how close and how far that anchor and tune take you. Myself, I do it the way I described because my goal is to get optimum accuracy at all feasible ranges, and I'm willing to face-walk for it. When I do reach the absolute end of my pointing tether, I'll shoot POA or string walk the ranges beyond. But I'm not that good an archer yet.
The reasons behind all this are highly complex, I think. Arrow speed and arrow drop are clearly important variables - playing around with a ballistic calculator will show you that bows tuned at five yards should shoot roughly the same (as each other) at 20, provided they are all in a certain speed range. And this speed range is pretty broad. But just ten yards further out, much bigger differences in arrow drop begin to show. These will obviously affect any aiming method. But with pointing, other variables come into play as well. A lot of it has to do with optics and the human eye, and I'm not sure some isn't individual.
As an experiment, just to demonstrate the role of optics and species-specific eyesight, point at something with both eyes open and using the arm beneath your dominant eye. Then move back. You will automatically raise your arm to continue being 'on target' - as seen with both eyes open. Close your non-dominant eye at any time, and you will perceive your finger as
beneath the object you are pointing at. Now, that is obviously where you would want an arrow to be from a gapping point of view, too - but up to a certain distance only (point on, after which you would gap
above the spot).
Even if you '3D point' at a distant landmark, your '2D finger' will still be beneath it (i.e. when viewed with your dominant eye only). Likewise, your pointed arrow will never rise above the bull's-eye when viewed in 2D from behind. That means that your pointing must inevitably go 'wrong' at some stage or other - at the very latest when you reach the range that would be point on if you were gapping.
In short, this means that your 3D eyesight and arrow drop are in sync for pointing over a certain stretch, using a certain anchor and tune. Further out (and perhaps also closer in), they aren't.
Speed isn't everything. Speed and optics/eyesight are - in very intricate combination. That means a lower anchor and a shorter arrow can extend your pointing range, just as more speed can. An almost 33" shaft and the arrow nock above nostril level make for a rather short (initial) one in my own case, despite a fast set-up. Unfortunately however, the effects of anything you do to counter-act the limits of pointing aren't one-dimensional. Start out with a lower anchor and you will be on an even lower one much sooner than I. Add speed and you will probably need to raise your nocking point, thus shortening the range gain you expected. Trim your arrow and it becomes a less accurate sighting device, and so on.
All that said, and bearing in mind that I still don't really understand the details scientifically, more speed is always a good thing for pointers - within the limits of your personal strength, plus those of the arrows you are able to shoot with a certain bow and their overall weighting scheme. Obviously, if you can get a 300 grain arrow to shoot well with a fast 55# bow, you will gain some range. But spine and FOC considerations soon come into play, not to mention mundane things like shaft prices. Bottom line is: If you can shoot a fast, heavy bow, do it. But you won't gain nearly as much advantage as a gapper would. Pointing has a somewhat socialist effect.
Perhaps I should add that any tuning you do must also be within the limits of overall tuning wisdom. Regarding elevation/nocking point, that's almost automatic. Tune for your arrow to hit where you're looking height-wise, and the nocking point should also be acceptable for any other aiming style. But for windage, first work the other way round. It's probably best to tune your arrow and plunger using some form of gap technique until you've got used to the pointing style of aiming. It should then hit true when you point with it. Otherwise, you need to work on form (not your plunger).
Best,
Martin