err, you can already.

hover over the comment near the borders, when it becomes a crosshair, left-click and drag the point to the element

I had tried a few things, but always from the center or corners, not the edge. That helps me not lose the comments when the elements move. I learned something today :)

I would still like it if those tied comments moved during the "bumps" that happen when you insert an element - leaving them alone during a manual move makes sense to me, but at least there's an arrow for me to track.

I'm going to change the title of the idea to reflect that :)

Thank you, J!

-- Ritchie

...and it turns out the auto-bumps happen as well. Why couldn't I have discovered this by accident in all this time? ;)

Well, one of the reasons is that starting with P9, you have to hover over the edges instead of inside the element, like any other element. Pre-9 it was far more discoverable. The rationale is that starting with P9, the OS wizards can enter hyperlinks in comments (I don't think it's possible to do that yourself), and these must be clickable even if not in edit mode. But it stinks.