Orbis was the first to merge it, believe that was done when you were still here.
RifE was next, and has probably done the most to change it.. Still done the same in python, but leaders have a new 'Leader Status' field, similar to alignment, which determines how they work. We've also split Minor into Minor and Emergent, with Minor being generally the same as Major leaders (for now) and Emergent having a strong trait (typically unique) and able to gain more, as in your mod. LeaderStatus is also displayed graphically in the scoreboard.
WildMana has also incorporated it, though I think Sephi went with the Emergent name... Python is the same as in here, no Leader Status tag.
I believe that all three mods have game options blocking Minor Leaders (Or Minor+Emergent) from spawning, or blocking Major leaders from spawning.
Pretty sure that's it, though I may be wrong.
Edit: Though I don't think any of the mods are using minor leaders for Infernals/Mercurians.