In terms of function, did the Suntour power shifters provide actual differential resistance between down and up shifting as Simplex retrofriction do or did they just provide a ratcheting tactile feel to the rider? I do understand how just providing a tactile/ratcheting feel would help with shifting, as IIRC, I did enjoy such with my former Peugeot's original Simplex stem shifters. which seems to be similar to Sutour's Power shifters.

Chombi