You will need to consider this with whether to add flags on boundary=administrative . There are only 2 flag:wikidata= with such use. Wikidata shouldn’t be very difficult with SPARQL or something, which is more general than Overpass for OSM only.
Instead or alongside similar to flag:wikidata= on =flagpole , this might be used for the physical emblems mounted or printed on structures , doors and gates, etc. But then it should be coat_of_arms:wikimedia_commons= (3 flag:wikipedia_commons= , and 4 flag:image= that can be converted to the former). This logically doesn’t neglect the use of coat_of_arms:wikidata= either. The 63 coat_of_arms | Keys | OpenStreetMap Taginfo are already in the =File:* format, but lacking this suffix specification.