The on-battery toggle bought a fraction of a watt while the radio
idled -- twenty-some minutes across a full discharge in the best case
-- and paid for it with 20-300ms latency spikes on idle links and
outright link drops on Intel BE200/BE211 firmware. NetworkManager can
keep power save off natively with one conf.d line, which replaces the
udev rule, the setter script, and any per-card deny-listing.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>