Thanks for the response, and for the various links.
Luminar021's edits may have improved slightly, say from 90% bad to 75 or 80% bad. It isn't worth going to the effort of undoing the majority of them, but they're certainly not making Wikipedia better.
I have another concern, though. Based on the links you sent and the auto-generated tags in the edit history, Luminar021's tasks are "Newcomer task: copyedit", but the actual edits they're doing are "add a link", so they're not following the newcomer workflow in any case.
And by "opaque" I meant that I wanted to see if the newcomer system was really telling them to make these changes. Now that I've played around a bit with the system I gather that it doesn't have assignments per se. But I also want to see what the instructions were for creating wikilinks, which I would need to know to meaningfully discuss what a newcomer was doing, and there doesn't seem to be any way to see this. Finally, it would be useful if there were a way to find newcomers' mentors, so I could tell them, "Hey, your mentee is screwing up" and not get further involved.
Feel free to incorporate these concerns or not, as you see fit.
Regards, ~~~~