Hi Marph
I know that this is a minor issue, but only mention it if this is easy to fix and only if impact all this plug-in users.
In TB if you select an email and trying to send this email to Joplin using a contextual menu option, TB shows:

a duplicated Joplin option (see the attached screenshot). I confirm this is not a real problem but only mentioned it.
Thunderbird 115.0
Joplin export 0.0.5
OS Ubuntu 22.04