I was grumpy, but luckily I had an answer to a password related question that I could over-explain. Now I'm feeling a bit better for having accomplished something. :-\
There is no advantage. A password-based KDF already behaves a lot like a hash function.
There is no weakness to pre-hashing a password if you use a proper hash function.
If the probability of a hash collision is small then hashing does not reduce a cracker's search space.
However, if the ...
Who's calling me a nerd?! Let's see how confusing, incorrect, or incoherent that is after I get some sleep.
That's a weird answer. I have never downvoted an answer from him before finding something definitely wrong and screaming incompetence. This answer I just can't understand. It almost reads like bot generated text. It doesn't look like he understands what he's talking about. But benefit of the doubt. I have no idea what he thinks those words mean or what he means to say.
I think it's best I don't comment, vote, answer, or do anything that might lead to him staying on the active questions page for any additional time...
I was wrong. It looks he might actually be interested in learning. There are like minded people that publish stuff that looks like his writing. Arxiv, ResearchGate, MDPI. Distilling entropy. Bits per byte. Trial and error pseudo-math. "Photonics"
It's funny that he suggests dropping high order bits until you fool an auto-correlation statistic. Sounds a lot like eyeballing an oscilloscope and judging whether or not your signal is sufficiently squiggly. Or not getting the fundamentals of statistical hypothesis testing.
@MilkyWay90 Maybe try r/codes. Not one of the normal cryptography subreddits, because puzzles, code breaking, and ancient encryption methods are off topic there.