overly strict semantics

One change I would remove is seq_cst stores and memory operations; and in their place I would rather have operations that behave as if they were enclosed by seq_cst fences on both sides, like for example Linux's atomic_add_return. The difference is that a RMW seq_cst operation can be reordered after a subsequent relaxed load, but that's not the case for LKMM and atomic_add_return. So this would actually make semantics *stricter*, not looser.

I don't have high hopes that this would be accepted now, but maybe it would be since "almost nobody will need anything but sequential consistent variables" has been shown wrong.

The other thing that still hasn't been fully formalized is out-of-thin-air values. Everybody agrees that they won't happen but strictly speaking they aren't prohibited, or weren't last time I checked.