Surely Scott knows his stuff?? I actually have read a bit of the paper in question ... The source of noise he expects is due to engineering contraints :/

He himself says: "conclusions about small-scale quantum systems from insights of the theory of computation that are usually applied to large systems" ... The engineering is obviously gonna play a massive role .. It's kinda like someone came up with a proof that says if you u use traditional engineering then you can't have semi-conductor electronics (agreed with pre semi-conductor technology ... you can't)

For example, look at this math formula I discovered: https://math.stackexchange.com/questions/2888976/the-definite-integral-problem-with-a-twist

I was a process of years. It took me years to identify a problem (mentioned in the question) that I felt intuitively the solution existed. I then attacked the problem for another year even lowering my standards of mathematics to derive it "conjectured formula." After which I started attacking the conjecture with simple to crazy examples. This gave me insights of what the problem I was attacking was really about (it was more convoluted than the pro…

For me to even say you might have to learn x, y or z. Maybe some combination can help you? I'd recommend you try some physics modules (maybe skip 1st year if your confident with classical mechanics and calculus used there?) ?
Usually in physics the math pattern is math or theory A is one level below it's fundamental counter-part of theory B ... So even if I did give you the right suggestions. You would have a lot of things to catch up before you could even touvh the advanced mathematics your theory requires.