A user known as xorvoid discovered that if you cut the UART trace on the PCB while the router is writing the kernel panic log, the eFuse register resets to a debug state. In this state, the "exclusivity" flips: it will accept any firmware except the official OpenWRT build. This led to the first known port of FreeBSD to the W1700K, purely out of spite.
: Enabling 6 GHz in the U.S. may require a specific patch to comply with or bypass regional locks in the firmware. w1700k openwrt exclusive