The author even admits this "is better than doing no test at all".
“ (…) you can just mimic the behavior of complex numbers using pairs of real numbers (and appropriately tweaked definitions of operations). (…) What Renou et al are actually claiming is that if you start with quantum mechanics, and then remove all operations and states involving non-real numbers, and then try to emulate what was lost using what remains, you will fail in an experimentally detectable way”
Meaning it’s actually totally possible to only use reals to encode the complex Numbers, but not to also remove all operators which do the same things as the complex numbers would.
"actually you can replace with something equivalent"
"i said just remove the math, not replacing it"
so, what's the news?
It's also a matter of reputation. Everyone knows everyone and have read a few of the previous papers (or papers of the advisor/coworker/whatever). If the previous papers were good, it's a good signal to take a look at the new result. If the previous papers were dubious, you skim it in case there is something interesting, but may just ignore it.
[1] Perhaps the exception are medical trials, but they have a lot of rules and paperwork to avoid lying, error, misrepresentations and other nasty stuff. Anyway, after reading a lot of ivermectin preprints during peak pandemic, I'm not so sure.
I'm not sure how to solve it, that avoids wasting money and time on flat earth research.
(I think the researcher time is more critical. If 10% of the money is wasted, nobody would care, some research flops anyway. If someone wasted 5 years doing flat earth research, it's difficult to get back. (I'd ask x5 of the money in exchange of the reputation damage.))