rhschwartz1957 When you are done with the holding process how thoroughly did you rinse it off? You can set it in a Polly pan or lug at an angle in your sink and let freshwater run over it to reduce the saltiness BUT since you haven’t had this issue in the past I doubt that is your issue. Is that additional rub you put on it very salty? If you put some in your hand and taste it, does it still taste good or is it formulated more to work with long smokes like ribs?
I wouldn’t go below 4 days even on your 1.5" thick bellies. Theoretically, it would be cured in 3 days but since you are only partially cooking the bacon then I would want that extra day to make sure!