Flywheel mass and rev limit are 2 separate things. Lighter flys in general will allow the engine to rev quicker, slow faster, screw up idle and engine balance, and accelerate quicker. Your rev limit is decided by reciprocating mass (piston + con rod mass, valve + lifter mass) and valve springs.
That little blip you are trying to get rid of is usually seen in fly-by-wire cars for emissions. Cable linkage cars like ours are not immune, as the idle stabilizer valve may open to allow a little air past the butterfly. I am actually trying to track this down too, as it tics me off immensely.