Thanks Bill! I am unfamiliar with (but now learning about) soft bisques. Yes, I glaze to 2175F, and after a 12 min hold it's around cone 6.
I like your idea of the 1200 tests, but because this work is time-sensitive (and I have a lot of other firings going on), I'm more inclined to just redo the pieces.
As for the rebisque, I am reluctant because it risks cracking the piece, but perhaps it's worth a shot.
Your third suggestion is appealing. My bisque schedule goes 100f/hr from 1200–1860 so maybe I just insert that into the glaze.
Thanks!!