I must be one of those individuals. I've shortened my draw about 1 1/2" over the last 40 years and take the time to tweak the heck out of my draw. It does change a little from bow to bow but not much. I had two Martin Nemisis set up exactly the same---almost. One was 26 3/4" and one was 26 13/16". There may be other factors involved, but my shooting showed that 26 3/4 is almost perfect for me. The one with 26 13/16", although I can't feel a difference, just doesn't shoot with the same consistency. Not much different, but enough that it shows up down range.3/8 isn't all that much difference , when you consider that the wing span/2.5 method is only a starting point to get your bow in the ball park. so many factors come into play for the final fit, that it's impossible to use it for anything but a rough idea. if that 28-5/8 has your anchor in a good position and you're not stretched out tight or leaning back, then g with it. you may find that you need to make a few small changes either way after you shoot for a while.
the main factor in deciding when are where you should be, is how well developed your release execution is. the better it is developed, the more critical the correct draw length will be in respect to how well the draw length lets your release execution run. people with very well developed and ingrained release executions, will be sensitive to as little as a twist or two, of the bow string.