Well, I had better respond.
Hoffman's academic credentials and experience initially look impressive. However, take a closer look. He does not seem to hold any qualifications or academic position in the hard sciences, apart from computer science. He is described as a "quantitative psychologist". His Bachelor's degree is a Bachelor of Arts.
There is nothing there to suggest he has any academic qualifications or experience whatsoever in relativistic mechanics, quantum mechanics, etc. And that is important, because Hoffman's conjecture (and it is just a conjecture) has fundamental implications for these very specialised areas of Physics.
Are you really confident you understand quantum mechanics and string theory better than he does?
That is a red herring; I didn't claim to. (In fact I don't understand "string theory" at all.) Hoffman tossed those terms out very flippantly in the first video. Hence I wondered.
No I don’t think Donald Hoffman thinks the material universe exists independently of consciousness.
Yes, it it clear from the second (8 min) video that Hoffman's conjecture is that the universe does not independently of conscious.
Intriguingly, in that video, there were a couple of references to "data" and "evidence", but we are not given any info on what that comprised.
Hoffman made detailed reference to the "observer" in quantum mechanics, towards the end of the second video. He appears to make the link between "observer" (a shorthand expression used to try to explain relativistic mechanics to a student) and consciousness. I can sort of see how he arrived at his conjecture. In essence, he has mixed a term used to try to explain a phenomena in Physics, with a concept that that term also needs to be present for that phenomena to occur.
The simplest analogy I can think of is as follows. It would be like somebody asserting that: 1. We need a microscope to view bacteria. 2. Therefore bacteria can not exist without a microscope being present.
PS: I didn't watch the third video. I saw it was 25 mins long.