Not really because ABI's are already architecture specific so they already do stuff different for other CPUs. Similarly, their are already a variety of attribut

Not really because ABI's are already architecture specific so they already do stuff different for other CPUs. Similarly, their are already a variety of attributes that can be used to explicitly control the ABI of the top of my head things like packed structs and function calling convention are common and in several languages (C, C++, rust and zig).