Yeah, it is for multicam shoots, mostly live concerts. It will help a lot for sync.
I think you are out of luck, when I shoot live performances I mainly rely on the fixed ground cameras with audio or TC sync and for the drone work I just mix in a few seconds here and there of shots of the crowd or the stage, I don't try to sync the two exactly.....with the drone so far away (since it can't fly over people anyway), and the wide angle lens, no one can tell they aren't in sync.
If it's an active band and someone is jumping around on stage, then you might want to get the sync a bit closer, but unless you can see their lips moving to the audio there is no way to tell that it is not exact.
There might be a way to set up a visual TC sync where you put a visual TC clock in front of the drone camera and start recording each time before you take off then use that to sync later.....but I don't know about you but they don't pay me enough to try to be that precise, if my clients had that kind of budget I would be lifting Reds into the air with proper TC sync.
Something like this is what I had in mind
. You would run the TC signal into this device, then place it in front of the drone before each flight, hit record on the drone camera, then not stop recording while in the air until you are returning to land. Not very efficient, a lot of wasted video as well, and you would still need to manually find the TC points in the ground video cameras to sync with, but it would be precise and easier than manually syncing. I looked up Deity TC generators (I use Tentacle Sync) and it looks like they have a visual TC output on the side of them so maybe all you would need to do is sit one of them in front of the camera instead of buying something else.