Makes the behavoral change of #13263 without the underlying refactor.
Hopefully this clearly safe from a perf and GC perspective, and will
make it easier to benchmark #13263.
This is supposed to firstly improve the docs as they are, and secondly
hint at how the core conceptual information ought to be moved to the
store derivation section of the manual.
Co-authored-by: Jörg Thalheim <Mic92@users.noreply.github.com>
