With current ISO C++ velocity and the stance to keep doing language evolution in person meetings, I don't think Herb's proposals will ever come to be, and even if they do, it won't matter when they most likely can only make it post-ISO C++26 with best efforts.
Needless to say I didn't restrict myself to pass-by-value (compatible -> structs with ptrs are problematic as well) style, which seems quite restrictive