but in reality he construct's - to my opinion - no new knowledge. A theory is new, if it allows, contrary to an "old" theory, to make 'new' predictions or it allows to better understand 'old' facts.
You are certainly entitled to your opinion, but I would suggest to you not to simply brush him aside after casually reading one paper. He has written hundreds. Over 6,000 pages. Also, his 'simplistic' math is a deliberate choice. He is capable of doing complicated math, but he believes (and has shown) how it's easy to obfuscate and fudge complex math, so he likes to keep it simple. Actually physics before the 20th century used to be done with straightforward algebra. It's quite remarkable what he has been able to accomplish with 'just' algebra. I view it as a sign of parsimony and clarity, rather than simple-mindedness.
I also completely disagree with your appraisal of what Miles has accomplished. He constructs a lot of new knowledge, mainly in the form of a theory (supported by math) that provides a whole new perspective on physics. Well, it's not wholly new, since it is deeply rooted in many long-standing physics equations and solutions. And in fact much of what he has done is to go back and find errors in long-standing physics 'solutions.' Perhaps the most significant of the 'new knowledge' he has brought is his discovery of the charge field, composed of what he calls b-photons or charge photons. This discovery has enabled him to write paper after paper after paper where he is able to explain things that mainstream physics cannot explain, and in many cases explain things they haven't even asked about. And on top of that he is able to explain things they have but with his own postulates and method (such as wave-particle duality which is only the appearance of duality). I think it's quite remarkable.
As for your point about dark matter/energy, while it's true that we don't *know* how much dark energy/matter there is, current estimates do put it at around 95%. They need it to make their equations work. You know, he didn't just accidentally multiply some numbers together to come up with 1/19. They are derived from his theory. I personally find it quite remarkable that on the basis of his theory he was able to construct an equation whose product was a number that "just happens" to hit at the right ratio. Here are a couple of papers of his that deal directly with the dark energy/matter 'vaccum catastrophe':
http://milesmathis.com/dark2.pdf
http://milesmathis.com/catas.pdf
But put that aside. As I said, it's only one out of many standing scientific mysteries that he has been able to solve/explain or shed light on. His explanations follow clearly and logically from his theory and are fully consistent with it. This doesn't just happen by chance. I would actually call that new knowledge.
And as for testable predictions, there are several:
One is in the paper I linked to on the double slit experiment:
Another is about the heat of the Earth:
http://milesmathis.com/hight.pdf
Which had already been partly validated:
http://milesmathis.com/core.pdf
Here is a prediction about Jupiter bending light:
http://milesmathis.com/call.html
Here is a prediction related to quasi-crystals:
http://milesmathis.com/mangal.pdf
Ah, and here is some correspondence he had with a scientist doing NMR where he was able to make a prediction that was tested and validated:
http://milesmathis.com/main2.pdf
Finally, and I don't know if I mentioned this in an earlier post, but I can't be bothered now to check: at ICCF-18 Steven Jones gave a talk where he said that he doesn't think the anomalous excess heat from Pd-D experiments comes from fusion, but rather from something he calls 'Freedom Energy.' Well, it's clear to me that this Freedom Energy is nothing other than Mathis's 'charge field.'