Hi Tony,
showing my ignorance here, I don't think i quite understand what a "stop time" pattern is/or should be, and how stop time is actually used.
The 4 variation composers automatically keep looping ( so could they work? ), not sure whether the fill 1 & 2 composers could be used.
The pads would only give you 2 instruments and normally they're played in sync with one of the variations.

Just wondering if there are any styles with a stop time pattern that I could try.

best wishes
Rikki