Rated 5 out of 5 stars

While editing, can't copy or cut anything. Paste works as expected.

Update: C-E responded quickly with a work-around. Tbird is the culprit. Thanks.

This review is for a previous version of the add-on (1.0.2).  This user has a previous review of this add-on.

Sorry, this is a bug in Thunderbird, see
https://bugzilla.mozilla.org/show_bug.cgi?id=1692327
I cannot do anything here.

Only the keyboard command Ctrl+X for cut seems to work.
As a workaround for copy, you can do Ctrl+X followed by Ctrl+V.