^^^ i do that all the time in the E30.
with the CC set, you can press the gas pedal and there will be no resistance until you take up all the slack on the throttle cable. then i can pull open the throttle more to speed up.
i do it when i set the cc on the highway, and then i need to get over to pass someone who is going slower than what my cc is set to. then once i pass them and get over again, i let go of the pedal.
i also notice the CC letting off the throttle too, when going downhill. when i look at the MPG meter the needle is way past 40mpg, then when the CC reapplies the the gas, then it goes back to about 25mpg.
i thought the E36 and E46 might have had newer setups tho, different from the simplistic E30 design.
just my two cents