The wizard asked for it, coupled it to a neighbour, listed it in the
summary as applied, and wrote it to the config. No code in the plugin
has ever read it. A wizard that collects a decision and reports an
effect that does not happen is worse than one that never asked.
Its partner, FilterIncludePreviousSessions, has a real reader and stays.
The coupling was two-way -- switching this on forced the partner on,
switching the partner off forced this one off -- so removing it leaves a
single checkbox that means what it says, and the summary line now
reports the setting that actually took effect.
The self-test asserted that skipping step 3 does not overwrite either
field. That assertion is rewritten rather than repaired: it was pinning
the null-semantics of the wizard's pending state, which still matters,
just with one field instead of two.