Airline-dependent but I have been able to browse HN over the "messaging" plan. Sometimes its just a data rate restriction, so HN works fine.

I don’t remember the exact verbiage, but one of the airlines hints that it’s the bandwidth-heavy “websites” (domains) they’re liable to be blocking.

Even for genuine WhatsApp traffic the speed is limited so severely that loading a video or image someone sent you is nearly impossible.

TCP would be too wasteful - Whatsapp already has retransmissions/etc. You'd want to proxy at a higher layer such as HTTP and just relay HTTP messages (or ideally QUIC traffic so that you take advantage of header reuse/compression, etc - but somehow disable retransmissions since you're already on a reliable link).

I think this is a premature optimisation.

I'd rather have a straightforward TCP-over-WhatsApp proxy than some hacky thing that only works for HTTP, has to peek inside your TLS sessions, etc.

I think that's essentially what my HTTPS proxy does; except rather than actually being over WhatsApp (i.e. using WA messages or w/ever), the SNI tricks their authorization into thinking I'm using WA, while I am connecting to my proxy.

No, yours would immediately break if they whitelist IPs. This one is pretty much officially sanctioned WhatsApp traffic.

Ah right, if they also impose IP restrictions this would not work

You’d get banned from WhatsApp pretty fast doing that.

Nothing like asking some data center far below to generate AI art from 30,000 feet.