htap_region_tier1 and major_road services also have the attribute 'properties.aggregation'
When looping over all database fields to be filled with GEO-PEAS
(https://toar-data.fz-juelich.de/api/v2/geolocation_urls/)
one could profit from a common result structure.
Therefore, it would be an enhancement, if also the results from
htap_region_tier1 and
major_road services
would provide the attribute 'properties.aggregation'.