Following instructions are provided without any warranty, and may even get you in trouble legally. The instructions are provided for testing, learning, preventing e-waste, and should be use with care. We (including contributers + commentators) are not responsible for any damage to your device(s) or any legal issues.
Instructions have been moved to https://github.com/francoism90/asus-router. :)
Well, then I don't know what else could help....
(but at least you can use all other 5G channels without DFS and full power 😁. Sure, U-NII-4 would give you another 160 MHz channel...)