I live in Germany, and I can assure you no such check exists. I have one of these systems (although I don't plug mine into the grid, I store power in batteries and use it)
I'm not sure how the electricians protect themselves, I can only assume that they measure for voltage on the line after disconnecting from the grid, and then search for the culprits. Generally speaking any service providers inform residents well beforehand about outages, and there might be fines if you hold back work? I haven't looked into it, perhaps someone else has more info.
That assumtion is an annual cost. Although doing it for one year only would still probably reduce the homeless numbers considerably.
https://www.sciotoanalysis.com/news/2024/1/16/what-would-it-cost-to-end-homelessness-in-america