I think the solution to sticky cables is new cables and new housings which is not that expensive, just time consuming. My issue is definitely not the cables. It is absolutely the mechanism in the shifter unit, not the derailleur.

On the ride home tonight on the 16-in folder. The airZound air horn earned its keep at least twice. I am lit up like an emergency vehicle and yet people don't check the rear view mirrors before pulling u-turns.

I have my phone GPS feeding into my ear when I'm on the small bike and the speeds are deceptive. Because of the 2 and 1/8 in wide tires when it is just a smooth straight of head, the bike faster than it feels. But any change turn bump or whatever in the bike feels much faster than it's really going because of All the mechanical commotion and gyrations due to the short wheelbase and weird frame design. But it rarely feels out of control.