Can use it on flat highways, light traffic, and up and down grades with no issues.
I do that by simply keeping the friction set reasonably firm and use my throttle hand index finger to keep the GoCruise against the brake lever when twisting the throttle either back (to add more throttle) or forward (less throttle) at the same time.
Index finger on GoCruise to keep it against the brake lever.
Adjust throttle to new speed, either rolling on or off.
Relax hand and GoCruise is locked in new throttle position.
After using it for 50,000 miles or so on the NC do I wish I had a true electronic cruise similar to the one on my GL1800? It would be nice, but for $20 I'm pretty happy with this throttle lock and it does 90% of what I need it to do.