For reference , Fex is a translation framework for x86 to ARM much like Apple’s Rosetta2 and Microsoft’s Prism.

Valve sponsor development as it’s also the way the new Steam Frame supports x86 games. It’s also being used (as a fork) in Crossover Beta to replace the use of Rosetta2.

As noted in the article, Apple solved this problem six years ago by simply adding an x86-compatible memory ordering mode to their chip when x86 emulation became important. Yet another way Apple's chips lead the industry.

Well well well “modeless” has decided to finally see the light of modes