Hmm... Timed modes are bad? I toyed with the idea of a timed keyboard for mobiles/pads; a variant of the Hexagon game controls -- basically left and right butt

Hmm... Timed modes are bad? I toyed with the idea of a timed keyboard for mobiles/pads; a variant of the Hexagon game controls -- basically left and right buttons, turning a wheel of chars really quickly. (After a while with Hexagon, you get really good timing.) The keyboard would need some additional way to fine tune the last selected char a few steps up/down on the wheel. I assumed that similar models have been tried and found too slow. Or too demanding on concentration.