Here is their own statement, which has more info and context: Kitemill Breaking Records for Automatic Operation It talks about a new endurance record for its own system, not AWE in general.
The article I linked in my previous comment has the handwavy Kitemill’s KM1 pilot system recently covered more than 500km during five hours of continuous operation, setting what is claimed to be a new record for AWE, which is bad writing as they should include a source of that claim, but still is probably true. Your system is stationary so that is a different record, and I don’t know what records SkySails set for example.