http://u.qdnx.org/file/simsa0-20150131T211540-umpvwtb.html
This is interesting! You conceive of the growth of the federation in terms of the number of servers/nodes involved (and whether it increases). I see it primarily in the number of people using such nodes and the number of (mutual) followings that thusly interconnect the servers/nodes. Your take spreads federation outwards, mine rather inwards.