It should say "When used over HTTP/1" instead of "When not used over HTTP/2" because nowadays we also have HTTP/3, and browsers barely even use HTTP/1, so I would say it's pretty safe to ignore that warning.
> Unless you mean on HTTP2?
Any version of HTTP that supports multiplexing.
> But aren't WS connections also multiplexed over HTTP2 in that case?
There is RFC 8441 but I don't think it's actually implemented in the browsers.
It should say "When used over HTTP/1" instead of "When not used over HTTP/2" because nowadays we also have HTTP/3, and browsers barely even use HTTP/1, so I would say it's pretty safe to ignore that warning.
> Unless you mean on HTTP2?
Any version of HTTP that supports multiplexing.
> But aren't WS connections also multiplexed over HTTP2 in that case?
There is RFC 8441 but I don't think it's actually implemented in the browsers.