Minor bug in engrave mode changing trill length

When changing trill length in engrave mode, clicking on the trill line adds a box to the end which you can drag left or right. When dragging the box left or right, the box suddenly flies up to the top of the page (dragging still works though) and when you let go of the mouse button, the box reappears where it should be.

Thanks for the report. It is indeed a minor cosmetic bug, which I’ll fix later.

But it seems impossible to shorten the trill line past a certain minimum; and it would be good to be able to remove it entirely. Is that possible?

To remove it entirely, select the trill line, open the Properties panel, and set the ‘Has trill line’ property as desired.