I don't get it.
There is no need to disclose your online identity when registering as a member of the charity (a company limited by guarantee).
So me [User:LoopZilla] and me "Gordon Joly" are distinct. I have chosen to link them up, but I didn't need to.
Companies House has no idea that the person who is a director of two companies (one is a charity) is also [User:LoopZilla] on several Mediawikis.
Gordo