Will this disrupt other signals in the ISM band? If E2E efficiency is 60% there's maybe 30% radiating uncaptured? 400w is enough to jam anything else using the band for a long ways, maybe a kilometer?
I'd imagine they'd never get approved blasting 400w per kW erratically.
We are using a strictly point to point collimated beam that is expected to meet nothing but clear air. It shuts down if/when any transient object is about to enter the beam path.
Also, don't forget that the important figure you should be looking at is power density rather than total power
You also claimed it's unaffected by rain.
Which is it?
Rain will trip the laser screen, as will fog.
Ergo, this will only work in clear air. Rain and fog will shut it down.