How does that work?
"If any equipment you make cannot survive or at least be adjusted then you fail."
Indeed. So if you put up a 20dB gain aerial and in due course someone in the high gain beam sets themselves up an ordinary home WiFi setup, you get an extra 20dB of their signal coming down the antenna lead. More, actually, because you have a roof (not indoor) aerial. But it'll be OK as long as they're on a different channel, after all there are plenty of channels to go round aren't there.
It's a good solution in certain specific circumstances, such as (hopefully) these.
Just don't forget the EIRP rules, that's all.
One person's explanation of how the EIRP stuff works: