Danke für den Hinweis.
Ich habe nun die Infos gemäß dem Wiki nachgepflegt und in Sites verschoben.

Ursprünglich habe ich mich hier etwas zu sehr auf die Presets in JOSM verlassen.

changeset/182488229

Please check note/5264537

Please check note/5260303

Thank you very much for the correction.

Re-added in changeset/181537676

After re-check the the wiki site of place=region and place=locality, I decided to continue to tag it as region.

Okay, fair enough, you’re certainly right about the very unclear and dubious boundaries. So a node is entirely reasonable.

My goal isn’t to force this relation into the database. Rather, I simply think it makes sense to include it in the database as a landmark. A relation has the advantage over a node of also representing the area’s extent.

All in all, I would now add it as a node.

Please check note/5256150

Please check note/5256142

This is by no means "arbitrary". The region is clearly documented in numerous sources. Only its exact boundaries are disputed.

Please check note/5254363

Which are these empty multipolygons?

relation/20460835
relation/20460836
relation/20460837

Which are these empty multipolygon?

relation/20460406