My suggestion for people who find cruise control makes driving boring, disengaging, and thus more dangerous is to instead focus on other aspects of driving - perhaps unobvious ones. It's surprisingly effective.

Personally, I use cruise control very often, and the attention freed up by it I typically put toward maintaining lane position and checking my mirrors more often. It keeps the trips engaging and makes me a safer, more consistent driver.

I'm also convinced that traffic flow would be much better if people used cruise control more often. Speed variability seems to cause excessive lane changes as a driver inadvertently slows down and the cars following attempt to pass so that they don't have to slow down too.