It looks interesting but I have lots of questions about it. I'm deep into AVX512 right now
so I'll follow up later.

It might be specific to RandomX (and probably cryptonight) because they were both designed
with specific cache usage in mind.

I assume the technique is to disable next line prefetching which assumes sequential access.
RandomX won't need the next line due to it's randomness so it's waste to prefetch it.

Edit:

It appears this optimzation is specific to certain algorithms and could negatively impact others.
To implement it would require using it only on selected algos. The algos currently benefitting
are not supported by cpuminer-opt. It would be a lot of work to analyze which supported algos
might be helped.

I'm also concerned about the system impact. This kind of  optimization may be appropriate for a
dedicated mining system but not for a multi purpose desktop. Changing the prefetch configuration
has system wide effect and will affect other applications positively or negatively, even when not mining.

There is no gaceful way to undo the changes. Miners don't usually exit gracefuly, Ctrl C is
the standard exit, or sometimes a crash. This would leave the system prefetch configuration
modified and would require manually restoring it.

I think I'll pass.