First thing to do is to verify that when fully warmed up the fast idle cam is all the way down.
At that point it's not possible for the choke to cause this idle all over the place when warmed up.
This assumes all those parts and correctly installed, well lubricated and moving freely.
If you still see RPM's varying at idle speed I'd look at other things like the timing not being back to the base setting (weights sticking/springs too light).
Also check the throttle plates to make sure they aren't sticking in the bores.......Cliff