If we would have real time cadence tracking on every trainer I might agree but in my Case (TacX Neo) there is a delay of Cadence and sometimes Zwift is saying for some seconds „80“ followed by „105“ but reality was I cycleded around 92 pretty proper.
This „sometimes“ is pretty permanent and to be true I have often no idea if Im really loosing a little cadence or its just a measuring thing.
I think this might appear because the trainer can only estimate cadence because of power fluctuation on the chain movement. I mean 1 rpm is not really measured - depending on gear its more or less chain movement so Neo Trainer must estimate because of power fluctuation of chain rotation which seems not always to run proper.
I just think a Button to activate Avatars Metronom Legs within the Settings wouldnt hurt those who are fine with the numbers.