The ideal downhill is just enough to balance the wind resistance so it is a roll that you don’t have to hold back. Without having to apply force you can concentrate solely on maximum cadence and style, especially with short cranks.
I actively studied keeping my feet moving in circles in my early riding endeavours. I attribute some of the success to a short stint of riding in shoes with slippery soles. Tonight there were a couple of times when I knew my foot had followed the 114 crank arc I had become so familiar with on the 26 and was moving just above the bottom pedal.