I play a bit of Crazy Time and one thing I've noticed is that the flapper seems to change in terms of its tension. It's really quite clear. Though this could just be that the more rounds are put through it, the looser it becomes with the wear and tear. I don't think it affects the odds in any way.
I suspect that's why the game goes down for a few minutes every now and again as they readjust it.
Pretty sure the resistance is slightly different depending on direction of spin. Wheel certainly appears to slows quicker one way than the other but would take that to be due to the fitting of the flapper and should be consistent across all spins. Should not result in the “backtrack” experienced above though.