Indeed, since this was about a multihub bot i assumed it was to link chat. Not to fake users.
I've looked into it, and it still is proper NMDC protocol, if the client doesn't support any special options, then $Supports doesn't have to be sent.
Hubowners using fake users in their hub will find a way anyhow, there are probably more scriptkiddies able to fake users than to write a proper hubchat link...
Allowing it won't be default on protected IP's though, i'll add an option for it that needs to be enabled for it
allow no $Supports to be sent on protected IP's.