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. :)
That's the way I do it now
Using services-start script and also service-event-end script (so it's running after every change made in wireless settings).
It's still more convinent to make the changes once using nvram which is also applicable to asuswrt and not only Merlin.