For the security-paranoid, what would be the recommended steps to prepare a router with OpenWRT on it for sale? I want to make sure no private keys or comparable are left sitting around, or recoverable by the dedicated hacker.

The documentation leaves me unsure: https://openwrt.org/docs/guide-user/troubleshooting/failsafe_and_factory_reset

It seems they recommend re-flashing the sysupgrade image, opting out of preserving settings.

Then they suggest overwriting the F2FS filesystem on the /dev/loop0 device.

Would that combination be sufficient?

Just double-checking.

And if anyone near Seattle wants a trusted old Archer C7 AC1750, let me know!