I don’t know about a guide, but I believe it’s still possible to rip 4K HDR using an HDCP downconverter . HDR/DV data is included over HDMI, the problem is that it’s all encrypted (along with the 4k stream itself) with HDCP 2 which isn’t publicly broken yet. This box (and others like HDfury) does some tricks to force a fall back to HDCP 1, which has been broken for a long time, so you should then just need a capture card that supports it.

Scene releases may have better/faster techniques depending on the streaming platform, but they probably wouldn’t talk about them if they did.

Yeah I wonder what possibly could influence smart/talented/motivated people to want to leave China for the USA. In the US, they will be denigrated by checks notes being given rights to the profits from their inventions?