The drama was because POSIX formally offered no way to get the needed semantics without crazy changes. Shells would have had to be made very very slow. And the

The drama was because POSIX formally offered no way to get the needed semantics without crazy changes. Shells would have had to be made very very slow. And the things made faster were already fast, and not even very important to have fast. When shells that trace back to v6 Unix depend on a behavior, that being undocumented is a bug in documentation.