This guy on YouTube made several videos reviewing these and also doing some WireShark analysis, also on NanoKVM.
Personally I'd never use these on an interned facing network. But they can still be handy for local only.
https://m.youtube.com/watch?v=yHhdTRVvDFU&pp=0gcJCQYKAYcqIYz...
i got nanokvm pro desktop a couple of days ago. looks like what was before is no more now. i run tcpdump for a while, the only outbound connections are ntp
Is the piKVM mode really piKvm?
there is a button to switch. didn't click it. i also never used pikvm, so i won't know if it "Really it"