Just ordered the Freewell variable VND 2->9 stop dual filter set for maMA2. Question is what are the appropriate settings for these typical flying daily conditions...
Sunny, Variably cloudy, Overcast, hazy, and cloudy?
It's hard to give you a direct answer because time of day, local weather conditions and the direction that you shoot makes a huge difference. My part of the world can be a bit foggy and possibly smoggy, so my sunny day isn't quite as bright as a sunny day in the crystal clear skies of Scotland, for example.
In general, you don't need any filters for hazy, cloudy and overcast days. Maybe ND8 for cloudy but bright day and ND16 for sunny. On an especially clear day, ND32... those are all just rules of thumb. You can use your histogram to check if you are under-exposed or over-exposed and adjust the filter accordingly. It can be hard to get it perfect since drones move around and lighting conditions change in relation to angle to the sun, but as long as you're not miles off, it's easy to fix in post.