The two defects that were holding the flip back are fixed and verified on a
device, which is the standard this default has been held to since DR-161 shipped
a verified sub-path over an unverified one:
- returning from background audio restarts the renderer that is actually on
screen, instead of only ever reloading the <video> element (DR-196)
- the letterbox bars are painted, instead of retaining whatever was last in
the framebuffer (DR-194)
Evidence: handoff to audio-only at 69:54 returning to video playing at 70:18,
and clean bars across playback, the control bar and a rotation round-trip.
An explicit stored choice still wins in both directions, so anyone who turned the
flag off keeps it off — hence the null check on the stored value rather than a
bare === "true", which would silently re-enable it for people who opted out.
The Settings copy no longer tells users to leave it off; it now describes the
toggle as the fallback to the built-in web player.
The flag keeps its "experimental" name because it remains a suppressor of Rust's
backend choice, never a promoter: turning it on cannot produce a native backend
where Rust says HTML5.