For simplicity I am just talking about gramps42, but this applies to all related directories.

Right click on gramps-addons/gramps42 does not offer a delete option. gramps-addons does offer a delete option, and asks whether I want to keep the data on my computer (I said Yes), and whether I want to apply to the enclosed folders (I said Yes).

When I did this, it removed all the data for these addons from my computer, and removed both gramps-addons and enclosed folders in Explorer, and addons-gramps42 in Explorer (as well as the related data on my computer).

This was not what I wanted at all.

I restored my entire workspace from a Tim Machine backup (restoring all the files into the workspace was incomplete saying that I should check for files being locked - none seemed to be. So I restored "Workspace" to Workspace2" which worked, then deleted "Workspace" and renamed "Workspace2" to "Workspace"). This backup did not have any of the duplicated references. I don't know how I got into this erroneous situation, but I have now bypassed it (not resolved it).

If I get into this situation again, I think I would try moving (or copying) addons-gramps42 to somewhere else, deleting gramps-addons (which removes all addons) then moving addons-gramps42 back to my workspace.