When we had a manual, the M&R Acoma was the best one for us. Forced air, IR, foot pedal like you mentioned etc. Best thing to do was press the foot pedal just as you are moving the platens. This should turn the Acoma to line up over the platen just before it is there and make it get an even enough flash, since the rotation is slower and it would delay getting one edge, then turn off of the edge when the timer is over.
I bought it used, sold it for 85% of what I paid a couple years or so later.