Can you (collective you) start using it? Innocuous topics at first but make it a place where info is passed on. Discuss regional practices or the A&S fair. Promote events in the region or use it to promote ride sharing. use it to create a community. I know the Midlands heraldry, I had to look up the Pentamere. Issue a challenge to midlands to have more banners at Crown w/ Pentamere heraldry than theirs. Jara just made 110 scroll cases and issued a challenge to the rest of the Kingdom to donate enough blanks to fill them by Boar's Head. Issue a challenge to all of the regions to do something similar. Build a community. It's not easy but needs to be done and if the principality idea fails then you still have a better community.

You already have a regional A&S fair (granted I realize there are isssues there) and regional fight practices so changing them to Principality is really just a name change. The officers will remain just deputies of the kingdom officers even if you are a principality. That leaves champions, for me at least the Baronial or Kingdon Champion is just a champion to their particular royalty. It's a relationship between them so I'm not sure what a champion for a group does w/o a shiny hat to represent.