What it takes is a sufficient number of people asking for a forum for their particular church or movement. If there are none or one, no forum will be set up for that church until their numbers grow, and that's something we can all understand.
Occasionally there are a few together but so few that they are put--for the time being--with whatever other existing group is closest to them. That's how the Old Catholics came to be with the Anglicans. The Charismatic Evangelicals of whom you spoke can probably function well in the Pentecostal forum, which is distinct from the Cathoilc Charismatic forum, for example.
Might also look in Spirit-filled/charismatic for the charismatic evangelicals. I think I've seen Quakers in the Anabaptist forum. I think you are right about the family community churches fitting in with Non-denominational, unless you are talking more about a house church.
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"The Bible knows nothing of solitary religion." -John Wesley
charismatic evangelicals spread across many denominations, so I don't think they see themselves as centralized. But the spirit-filled/charismatic forum here would come close.