I think the unloader adjustment involves bending a little "tang" (i guess thats what its called officially).
iIts on the chokeside of the carb attached to the prim. throttlr shaft. You are correct in that there is more to adjusting the choke than what most would think. Fast idle,choke pulloff opening demension, the rod going to the flap, the unloader= all these things can be adjusted. The tang for the unloader contacts another lever which us attached to the shaft coming out of the choke housing. (btw, make sure you are getting wide open throttle on your linkages).