Jimmy, I'm not sure I agree with you. The acid in preferments, at the beginning of fermentation, is generally gluten strengthening, as is the bromate. The more chemically induced gluten development, the more water is trapped, not less.
If I had to pick a theory, I'd go with the slightly lower protein in the Gigantic is creating a wetter preferment, which, in turn, is driving faster fermentation. Norma, no promises, but I'd try a lower hydration for the preferment. You also might check it at intervals in the Hatco to see if less time might prevent separation.