Most have been created with JOSM and credited to my main data sources (the ones that stated the mere existence). However Maxar Premium was used to put everything right as to shape.
Thus they should all have “source:geometry=Maxar” added to them.
If I make a turbo overpass query to get all out is there then a way (that even I could understand) to add this tag to all?
There was a time when we did not have change set comments/descriptions so mappers used the source tagging to indicate where the new or revised data came from. The need for most source:*=* tags disappeared when change set comments/descriptions were added.
Going back to add source:geometry=Maxar would, in my opinion, be simply going back to add clutter to the tagging.
No, I don’t think it makes sense to add that as a tag to every object in a changeset if that source applies to every object in that changeset (and I’m speaking as someone who uses source tags on objects more than most people).
Instead, I’d suggest adding that as a changeset tag (“source” or “imagery_used”) when the changeset was created (iD will add “imagery_used” automatically, and JOSM will if you tell it to).
If you want to annotate a previous changeset you can’t change the changeset comment but you can add a comment to the discussion.