> I'm curious how you determine whether the user actually surveyed its existence or not? For example, on this POI https://osm.org/node/7056211216 , check_date was set to 2023-03-17, and the changeset from that date was someone doing tag cleanup with Osmose - almost certainly not a survey.

Yea, it's a mistake, I'll fix it. Determining this date is not an exact science, but I usually take into the account the name of the editor. Let's say it matches with a place name, or it's a well-known person who does the maintenance. I think that any edit from a business owner is safe to be timestamped as up to date, since he's basically acting as a maintainer of his own data and he's the highest quality source. He would have changed more tags if he felt that they need fixing. HubMiner sounded like one of the maintainers I had a few conversations with, and I know that he checks everything but often forgets to add timestamps. This is not him, so I'll revert that change.