I'm going to chime in here with a warning about "cruise control" ideas for motorized bicycles. They are not safe, guys. When the time comes, and it will eventually, when you need to get off that throttle 'now' fumbling for a release or trying to twist a lever to slow down can cost you precious seconds. Some motorcycles offer a cruise control option but those systems are as sophisticated and work like the ones in cars. They automatically release on the application of brakes and/or have a 'Off' control within easy reach. In a panic situation, on a motorized bicycle, a locked throttle can get you into trouble. Please consider this when experimenting with with your throttle controls.
Tom