The only thing I don't get is your Girder applications.
For instance are you wanting Main Lobby to control your HAI directly, or through the MLHSPlugin?
You might want to have Homeseer look at and control your HAI and then just interact with those Homeseer variables with Main Lobby via the MLHSPlugin.
For instance I have an Ocelot and Caddx security system and I use Homeseer plugins to look at and control variables for each of them. I then just use the MLHSPlugin and view/control those variables via Main Lobby, which essentially just passes the devices from Homeseer to the Main Lobby server.
Just my opinion, but since I don't have an HAI system, maybe others can chime in!
Regards,
BSR