moveLineUp and gutter markers

Try setting a “breakpoint” on the gutters demo, then move that line up or down using alt-arrows (moveLineUp, moveLineDown). The gutter marker doesn’t follow the line content; it stays on the corresponding line number. Is there a way to make the gutter marker also move up and down?

Yes, these commands just move text around and there’s no concept of a line with an identity in the library. So you’d have to write custom line-moving commands that also move your line-relevant metadata around.