Okay, so the votes were split evenly between "yes", "no" and "don't care". I gave some thought to it and figured - the snap to center behavior makes sense in the context of the old menu, where no cursor is visible in the menu, thus snapping it to the center (though primarily just a carry-over from Lemmix more than anything else) somewhat made sense as otherwise the cursor essentially reappeared in a "random" place on the screen - it made more sense to have it appear in one specific place.
With the new menus however, the cursor is always visible, so that's no longer an issue. And therefore, it shouldn't jump around. So - and this was already implemented in 12.12, and as I suspected would be the case, it seems no one actually noticed - I have made the change so that the cursor no longer snaps to center at the beginning of a level.