The directions say to have draw lenth and draw weight set before installing. If I installed this rest tonight, and say next year I put a new string on, the string on the bow right now will probably be a snitch longer then a new string, does this mean I will have to shorten the arm, or will the difference be so minimal that I won't have to make any adjustments? Thanks MWX

There is a turnbuckle, so minor adjustments should be possible, particularly if the arm would need to be shortened. The little change you are contemplating shouldn't affect much.

Better still if you know you will need some new strings, get them identical now, and in process. Idealy the strings should be set up the same, so if any problem comes up, you won't have to break in a new string, sights, tuning, everything.