What's wrong with current prosthetic?
In addition to wearing climbing shoes to add traction, amputee climbers often flip their prosthetic foot because of its large size.
Passive articulation works well for repetitive movements like running. But for sports like climbing, it requires limited ankle articulation to adapt to different surfaces.
Rock climbing is a strenuous sport, and it can be difficult for amputees who are missing strength from their leg muscles.