If you have spare axis (e.g. CH/
Saitek quadrant)even secondary commands like radiator, cowl flaps on axis is good because Quadrant lever give you a visual feedback of control position in a glimpse. On rotaries, like these in X-52, X-55 you dont have this feedback...
Radiator control on keys in il-2(original) is the most awkward choice possible for a control (R,R,R,R,R,R,R,R,R,R... Ops! one R more... try "reset" and start count again...)
Sokol1