Eh, Badkarma, i didn't get you
Ok, some more feedback.
I was wondering why US only appear when my government falls, while other european nations can declare independence without it.
So, first, i copied old revolt files, (those IGC ones), then i edited every fortress out (in NA, not in Europe), then i played.
Since i edited out fortresses, my government eventually fell, cause rebels wandered through NA provinces freely, and after that, both Iroquois and US always appeared, (strange thing that US capital was always in Mobile or Tuscarora).
Then, i edited revolt files again, deleting all additional provinces for US. No change, except US was only two province now.
Then i built fortress in connecticut, but due to rebels walking through all of NA, i didn't see that fortress fallen after siege, only instant takeover by rebels (and then fall of government eventually)
Then i annexed New Spain (which went independen some time ago, consisting of all former Aztec land, except one).Played again.This time both New Spain and US declared independence (after Gov Fall,of course).Strange thing that, despite in revolt files default capital of New Spain is Tampico, it always appeared in Tenochtitlan, makin New Spain pagan.
One more observation, it doesn't matter if provinces are controlled by one country, in last one New Spain grabbed all Mexican land, despite half of them was Spain owned (rebel controlled, though)
So fact that NA is not controlled by one country doesnt' matter. Main obstacle for appearing US is that apparently fall of government is needed

.And of course date of revolter beginning, 1700.
Maybe also low population values in NA provinces.
This case with government really puzzles me, i saw New Spain gone independent many times in my regular games, but i don't remember if Spain had it government broken.
I thinkn i will copy old GC revolt file and also try to buid fortress back in every NA province except US revolt ones, so i can see if after some time they will declare independence, without fall of government.Maybe i will edit province religions, so they will only rebel in required ones.
Anyway, for now it seems that only solutions are
1)seriously cripple England with loads of revolts
2)ditch US tag, and use it for something elso (if playing with Vinland turned off, since it uses US tag)
one more thing, i noticed that US revolter uses US flag, not Vinland one. It appears that IGC is more smart than i though, and, when playing with Vinland off, it uses old graphic files. But why Novogrod is named Finland and have Finnish flag?