> We can’t run the resulting binary. x32 is an ABI that impacts the kernel interface too, so these binaries cannot be executed on a regular x86-64 kernel. Sadly, and as far as I can tell, x32 is pretty much abandonware today. Gentoo claims to support it but there are no official builds of any distribution I can find that are built in x32 mode.

Which distro is this ? In debian I'm pretty sure CONFIG_X86_X32 was enabled in the kernel not too long ago, enabling this to work without issues. When I benchmarked it was on average 20% faster than x86_64 and used quite less memory for GUI apps IIRC - I think that for most utilities like coreutils, image viewers, file explorers, media players, etc. they'd benefit from it ; >4GB is only really meaningful for web browsers, compilers & interpreters, games and creative apps such as anything doing 3D, audio or large data processing.

And I assume most will default to X86S soon(ish)?

So is the only difference between "x32" (sic) and 32 bit x86 with PAE the fact that "x32" can use full 64 bit registers?