Start with a long playlist (long enough that you need to scroll down a page or two to see it all. Select the last item. Move it up one place.

Observe that the display briefly flashes to display the top page (actually now it stays on the top page until you press an arrow key, but it used to move back to where the selection is - I guess this is a side-effect of losing the selection). In the old version where multiple moves worked, this slowed things down a lot - something like 4 or 5 times at a guess. In the current version, I'm probably limited by my keyboard skills, because of having to re-select the item (did you ever play Daley Thompson's Decathlon on a rubber-key Spectrum? You'll know what I mean if you do).