Fused Prosthetic ankle
I wear a prosthetic left leg below the knee. My knee is fine which is why I am quite ambulatory. The ankle has some flex but no control. I fly an RV-12 which while not a taildragger does use differential braking. I cut a 1/2" thick piece of wood the shape of the top (toe end) of my shoe and epoxied a couple of velcro straps to it with which I can strap it to the toe end of my shoe. In the air this does basically nothing as I can push the rudder with leg action just fine. On the ground I can apply the brake by holding the right rudder firm (no toe action) and pushing with my left leg which applies the brake because the wood block is contacting the top bar (brake). This works well enough that I can lock the left tire and pirouette around it. Actually, the last couple of flights with new shoes revealed that I should not use them for flying as the toe end is so flexible that it is hard to get real pressure with the right brake as the toe curls up and doesn't push firmly.
I have been checked out for tail draggers (Citabria) prior to having a motorcycle. Yes, I got hit hence the amputation. Anyway, a while back I did an upset recovery exercise in an instructor's Citabria. I didn't wear the wood device but I could take off and land keeping the plane straight without braking, as it should be. The instructor did the taxiing but I have no doubt that the same block or something similar would work in the Citabria.
PM if you want to discuss further.
Jim