Toady and Funfly and anybody else, if you read the extract from the CAA medical site it explains in good detail the requirements for prosthetics being certificated. Please read it before giving simple opinions
And mini, it is not your call, it is up to the certification authorities of the registration countries. In this case it is now EASA and they are quite content to write the regulations for amputees and ensure they are carried out.
The rest is just hot air and un-educated opinions.