I want to do this using a rear coaster brake wheel, and apply a brake lever or cable to the sprocket (or its scalped remains) instead of a chain.
But I’m thinking that to get enough travel to engage and release the brake, I might have to use a lever multiplication scheme.
I never really thought about how many degrees you have to turn that sprocket forward & back to engage and disengage the mechanism.
Right now I’m working on the world’s cheapest no-name coaster, but internally it is the same as a Hi-stop.
It’s on a 16 inch 20 spoke wheel, and I’m thinking, ”good skurf candidate”.