^ Click on the vote icon now!!
I looked through the thread of feature requests and this topic comes up often but receives little votes. It is very likely that it gets little traction because there is a very small demographic on Zwift of para-cyclist. I myself am not a para-cyclist, but have many friends who are.
I would like to ask Zwift to build hand-cycle and recumbent bikes as an option just because it is the right thing to do. It will promote awareness among the greater cycling community, and will motivate many athletes to push themselves.
I know that Wahoo is currently pulling data from their users who are para-cyclist so that they can better meet their requirements. I am sure that they would be willing to provide that data to Zwift to help you build the models. As well as Top End and Catrike who are the leader in both hand-cycle and recumbent bike categories.
I will share this link to help encourage vote nonetheless, but, I hope that Zwift will champion this effort regardless of votes because I know that if they build it, it will have only positive impacts for our global cycling community at large.