Unless part of the event staff or for a specific purpose, I wouldn't get involved because you're bound to find someone who's bothered. Either way, shouldn't matter too much if these are "unmanned" kits, it's probably your drone mostly at risk.
The Kite flyers that I've seen at the beach were very acrobatic and very fast. I would think would be distracting for the flyers and the event itself, it's all about the Kites. JMHO.
First thing that crossed my mind was the effect of barrage balloons on German bombers.... y'know... a floaty thing on the end of a very long bit of string where something driven by propellers is trying to fly. One's bad enough, but a few dozen at...
I didn't see you mention stitching in your workflow?
It's very easy to stitch with the drone and the results are a lot better than doing it handheld with my Sonys.