I've read all the first thread and most of the second. It's such a fascinating and weird case.
I am a professor at a RG institution and have previously worked at a different RG and a post 92.
A few points where I think I disagree with some on this thread...maybe!
I don't think there is as much of a difference between the teaching at RGs and post 92s as some on this thread make out. Not defending LJM here for even a second. But sloppy practice like Arday's supervision is not normal in post 92 PGR supervision. I supervised umpteen PhDs at my old gaff, and they were absolutely rigorously done. Our depts also offered a solid education, often to much less advantaged students such as poorer students who needed to live at home. I'm proud to have worked there and think a lot of the rudeness is just snobbery.
I also don't think it's normal to read a job applicant's PhD before an interview. Generally, academic institutions respect others' awarding powers. You'd be warranted in assuming that a PhD awarded meant a certain quality threshold had been reached.
You would however scrutinise academic papers. Most non-professorial academic appointment panels I've served on would have something like - Head of School or equivalent, perhaps Head of Dept, 2ish members of the dept with appropriate expertise, and an academic from another discipline, such as a STEM academic for a hums appointment.
The sift would normally go like - public advert - you get lots of apps in, often well over 100. HR weed out the obvious weirdos, folk who apply for everything, those who don't meet the job spec like no PhD. The shortlisting panel (usually a subset of the interview panel) would normally do an initial cut and arrive at a longlist. At this point you'd scrutinise papers, and that would usually be the responsibility of the specialist academics. You'd then produce a shortlist which would be the interview list. Maybe 6ish people, sometimes fewer, with a couple of reserves.
Academic job interviews generally (not always) involve a presentation, often to a large group of people. When I got my first lectureship, everyone in the School was invited to witness the presentations. Sometimes it's a bespoke panel. Questions depend on the post but will often be along the lines of "talk about how your specialist research would be translated into our modules". When the presentations are done, attendees would generally produce feedback for the interview panel.
Interviews are maybe 45 mins to an hour and will test the candidates on things the dept needs. A couple of places I interviewed also had a separate "publications chat" where you had to sit down with the dept head of research or similar and work through your publication cv line by line so they could see what your eventual REF (research quality audit) return would look like.
Throughout all of that, yes EDI is important. I generally see it tested at each stage, so "why didn't we longlist any women? Should we reflect on that?" Type of thing. Which I think is appropriate
You also get a decent feel for people. Between all those interactions you usually could tell if someone was BSing.