The flyout containing the Delete commands is never large enough space to show them all without scrolling, usually horizontally as well as vertically. This doesn't seem to be a HiDPI issue, nor do I have any particular text scaling set in Thunderbird itself.
If the box has to be a fixed size, rather than responsive to its contents, I think making it way too large would be preferable to way too small.

The flyout containing the Delete commands is never large enough space to show them all without scrolling, usually horizontally as well as vertically. This doesn't seem to be a HiDPI issue, nor do I have any particular text scaling set in Thunderbird itself.
If the box has to be a fixed size, rather than responsive to its contents, I think making it way too large would be preferable to way too small.