I have a workaround.
Pokeys outputs the mpg to a user dro, and the increment button to a user led.
Brains multiply the dro as above, and use the increment button to set another userled (if mpg and userled 1100, then userled 1200)
Macropump triggered on the 1200 cycles the jog mode to continous, increments the jog inc button, jog mode back to mpg, clear led 1200.
A bit like rube goldberg, but it works!