It’s not that easy to have a good nozzle system without a very mechaninc-stable boom. It still easier to get the desired stability for it’s spraying system with those we have on heavy machinery.
In order to make the drone stable, you’d have to use a shorter boom than an heavy machinery can support. So, when using a short boom you’d have to make a bunch of refews on your reservatory and that would increase the time of an application and could even impact on it’s precision.
The wind is always a problem when you talk about spraying systems, and that problem getts bigger when you’re using any kind of flying machine.
I know it's the future, but it is always good understand the NOW limitations.