I too am waiting on this MOD. In the meantime, what I may end up having to do is modify the confirmation email that is sent to users after they register, with instructions and a link to a webpage (that needs to be created) with a "subscribe" button on that page. This, in turn, would take the user to PayPal where a subscription option has already been set up. The user would obviously need to complete the PayPal requirements for the subscription and the board administrator would manually have to maintain the records before approving a users registration request.
It's not the way I would like it to work, but it may work in the interim. (I would not prepare this as a MOD that would be submitted to the group. I'm not a php developer, but usually can find my way around things to make some changes to the different files.)