It might prove to be a great last line of defense, but close to the front, it will be targeted by artillery or over whelmed by drones.

The world isn't ready for Drone Warfare, I can't imagine the reactions of Western nations if they had to face what Ukraine faces every day. 200 drones is what flies in a minute along active locations on the front lines of Ukraine.

Couldn't you just fly low so that you'd be within the energy weapon's dead zone? I mean it doesn't look as if it can target anything flying at a depression less than 0°. Seems a few cheap fiber optic drones with a mortar lazily strapped to it and flying low could easily render this useless.

Why not just shell the shit out of this thing and the entire path to it with smoke (or real ordnance?)

If you don't have artillery, the first wave of drones could be sacrificially carrying smoke achieving an instant attenuation highway straight to this system.

Or just wait for a rainy day and then take it out. Expensive optical systems with large, expensive, glass focusing lenses aren't typically durable.