Many kilns have an upper limit programmed into them so that they will turn off if they exceed a certain temperature. This is to avoid a run-away kiln from a relay failure. Some controllers will let you by-pass this upper limit; it’s not recommended (because of that run-away kiln thing).
My guess is, however, that the kiln itself will just not get that hot because it is not capable, especially if it is a 120V kiln.
If you are firing low fire white clay for molds, 1650-1700 degrees should be fine. In fact, as long as you fire the mold hotter than the top temp you plan to take the glass that will be fired on the mold, you are fine.