This makes absolutely no sense
I use the cruise control all the time on the interstate and pretty much drive using those buttons when on the interstate because there are minimal adjustments in speed. But on multiple occasions I have accelerated using the gas pedal to pass someone quickly, then let off the gas and it goes back down to where I had set it. Never had an issue. As an example, I can set my cruise to 60 mph by hitting the set button and at any given time I can choose to just step on the gas pedal and it will start accelerating to a higher speed. I can then choose to hit set again to set a new speed or just let off the gas to go back to 60 mph.