Some of this needs to be answered by DT themselves, but I’m going to try and help you troubleshoot in the meantime.
To the best of my memory, the answers to your questions are:
- the add-ons are installed when you select to do so; from there on, installation is automatic, but my memory is that I have had to then activate the plugin in Mail manually (via Mail, Preferences, General, Manage Plug-ins…)
- no
- yes, no, or maybe. My experience with macOS is that it will often times ask for the necessary access, but occasionally either forgets or dismisses the dialogue before I get round to making a choice.
- yes (if, in preferences, you select General/Manage Plug-ins…)
Re. Full Disk Access: DT3 itself requires FDA to work properly. Mail and/or the Plugin do not. In Automation, I have both DT3 allowed to control Mail and Mail allowed to control DT3. I cannot tell you whether that is due to the Plug-In, or was something I set up along the way because I use scripts in both programs to perform actions with the other.
If the Plug-in is not appearing in Mail (under Preferences/General/Manage Plug-Ins…), however, any thoughts about necessary access are moot. This can happen (maybe Mail wasn’t really closed when the Plug-In is installed? It was a full moon and a wolf howled at the wrong moment, etc.)
Does this post help you?
Again, I’m aware I haven’t addressed the question of user-experience in my post - I don’t think that is for me to do; I don’t have the necessary metrics available (number of users having trouble vs user base; conditions attributable to DT3 vs to macOS).