I encountered this recently as part of maintaining whisper-cpp on Nix. Vector instructions make an enormous difference to this workload.

The ultimate best case was that the application itself would choose the appropriate code paths at runtime, minimising the possible divergence. We considered force enabling well supported instructions like AVX which are decades old but even those aren't guaranteed across a build fleet, especially with VM builders.

In short, they're a real pain and the application probably has the best information available to make the least wrong decision at run time. I don't think it should be a packaging concern.

https://github.com/NixOS/nixpkgs/issues/357736

Fedora 42, Gentoo Edition :-D