On TSR2 at least, and probably other flap-blowers, roll authority was obtained from the differential movement of the tailplane, plus the effect of the all-moving vertical tail; the wing as a whole being used to provide the necessary lift and the tail assembly the control in roll and yaw.
Pause for slight rant
A neat solution, unfortunately consigned to the "might have beens" by the then British government's "slash and burn" approach (so what's new ?)
Rant mode OFF
