I would like to point out that ( yes I am feeling generous today )
if the person opens up there winbox and ip cloud and sees settings availalbe for BTH, they may not be prompted to check out document where it states clearly whats in scope or out of scope regarding hardware and sit there spinning wheels why its not working.
So if the router cannot do it, it should not be available on the RoS greyed out or something.
If was not available or greyed out, then the OP should have checked the docs and made a self discovery.
Also to be fair to the OP, if you go to the BTH friggen Article, the limitations should have been stated by Normis on first post!!!
http://forum.mikrotik.com/t/new-feature-back-to-home-vpn/168434/1