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. :)
Finally i found solution, FW is not problem. But seems change parameters by wl -i eth6 and rest (7) (8) doing job, higher tx power can be achieved. And lucky have much more efficient wirelesses network with good range.
When i fully and permanent solve it will post here.
Adapter Temp 45C