The post mentioned that the introduction of these new algorithms brings compile-time improvements too, so how should I see this?
I assume you mean the first post of the PR? I'd assume it's simply outdated (or might not have been true to begin with). See https://github.com/rust-lang/rust/pull/124032#issuecomment-2181789935 for the perf run with this PR, it's showing quite a bit of regression.
Seems to be missing mlua at least: https://github.com/mlua-rs/mlua