Help with holes
The problem may not be due to the temperature. Check the kiln shelf — if it is warped/has a low spot, that low spot could be a source for trapped air. Flip the kiln shelf over and see if that helps, or fire on fiber paper (which would increase the chances of the air escaping, if the problem is air between the glass and the kiln shelf) — not Thin Fire or Papyros, fiber paper.
Jester’s Baubles Fused Glass Designs