Only one bot runs LeaderPLugin. You click "start" on that copy of HB running it, before starting any other copies of HB set to run PartyBot. You will see a single statement, "Remoting server started" report in the active log. If you do not see this line appear, figure the setup won't work. Close HB2 and start it up again, doing whatever you have to do until you see it reports the plugin is in active use. Now every other copy of HB you run will use the PartyBot from the HB drop-down menu. When you hit start, the PartyBot connects to the LeaderPlugin over the network. I'm fairly sure the the LeaderPlugin and PartyBot(s) have then established a bi-directional communication relationship. So this is important: You can't expect to run another copy of HB with PartyBot and have it communicate with a different party leader running LeaderPlugin; even if within a different RaF pair grinding on a separate continent, the follower is going to try and connect over your network's subnet to that first copy of HB running LeaderPlugin, wherever it may be..
The reason I've found this LeaderPlugin / PartyBot combination better than any other solution comes from this persistent over-the-network communication. This potentially allows HB to drive each toon as individuals as well as a fixed RaF pair and still have each partner watching over the other, pathing, not getting lost, etc. I see this as the first solid step in making the elusive questing-while-RaF configuration more reality than fantasy... This might be the best little piece of coding Nesox has done since Mr. Fishit... And props to Tjhasty's Multibox combo which preceded it...