Seriously this. Every single IC which has digital logic contains some number of undocumented test commands used to ensure it meets all the required specifications during production. They’re not intended to be used for normal operation and almost never included in datasheets.
It’s definitely a bandwidth usage thing, given their reputation for being informal in communications they could have been a lot nicer about that.
It’s really disappointing to see this from them, they were one the best priced VPNs out there claiming to respect privacy. Their support was also super helpful with my questions about their datacenter static IPs.