I have been considering adding an "AdditionalRegionsToControl" list of regions that would add the leader to multiple additional regions. This would keep the origianal add-on features intact and not interfere with any checks as the RegionToControl would be the main required regions for control to be given, and the AdditionalRregionsToControl would be optional, and ignored with left blank. Would need to also make sure the leader is removed from that additional list when a new leader is victorious.
I have breifly discussed this on the discord and figured an issue would be a better way to track it, and a good way to motivate myself to attempt it as a small practice project.