That might be easily fixed with a overdrive effect also getting turned on. Oh, and before I make this; does the clock stop when the input is turned off? Or do you need to pull some plugs and then reset it?
its been awhile since i last responded to this thread so a lot has changed.
push has been boosted big time. for example when i tested it on a ship i had made before with it I'm now able to achieve max speed (50km) in a matter of seconds. before i could only get 10-12 km on this ship so it got buffed big time.
now to answer your question. i don't think overdrive will change its max speed at least from what i know. push works a lot differently then just pressing "WASD" .
once you turn on a clock it will stay on until its turned off. if you want to put a time limit you'll most likely have to design a timer that switches the clock off. i suggest hooking up a modified monostable circuit to the clock as the primary input. that way when you activate the monostable circuit it will turn on the clock then after a time turn it off.