Every C6 node spends coexistence time-slicing on 802.15.4 -- a single 2.4 GHz
transceiver is shared between WiFi, BLE and 15.4 -- against a receive path that
provably delivers nothing. That time competes directly with CSI capture, which
is the node's entire purpose, and it matters most on a large fleet where the
50 Hz receive gate is already the binding constraint.
The evidence that it cannot receive is upstream's own (ADR-110 D1,
ruvnet/RuView#762): five configurations tested -- channel 15 and 26, OpenThread
on and off, promiscuous on and off, PAN-matched and broadcast -- and every one
gave rx=0 while TX stayed 100% reliable on IDF v5.4. ESP-NOW shipped as the
workaround and is what this firmware actually syncs on. The stack was
nonetheless still initialised at boot and beaconing every 100 ms.
Safe to remove: the ADR-018 byte 19 bit 4 "sync valid" flag is ORed from both
transports and the 15.4 branch is #ifdef-gated on this symbol, so the working
ESP-NOW path keeps setting it. c6_timesync_init is gated on the same symbol and
is no longer called.
Co-Authored-By: claude-flow <ruv@ruv.net>
