No, you can't use that button to go to the end after you've programmed the 30-second-skip.

What Bitt was telling me was that if you haven't programmed the 30-second skip feature, the button is both the "go to end" and the "go to beginning" button. Press it once to go to the end, and a second time to go to the beginning.

I had stated the original purpose of the other button (the back-five-seconds button) incorrectly. It was always a back-five-seconds button, and the 30-second-skip feature does not change its behavior.