I have a Galaxy S7 Edge, but a few weeks ago it was working fine
S7 is not on their list and too many report questionable issues with it. Some say it works, other not and maybe why it isn't on their list. It might never go onto their list too.
Fwiw, I have an older S6 'Edge' which is also not on the list (Edge isn't shown) and it is iffy. Sometimes it works 95% of the time, and other 5% the video breaks up badly. I don't know if the vanilla S6 phone works any better, but it might as it doesn't have the Edge's curved screen along with its fly-out menu which might make the Edge model consume more resources.
I also have a Samsung tablet and it is worse on video lag than the S6 Edge phone. Likely it is more under-powered and too many resources being used which is something Samsung and the carriers need to address and stop having so much bloatware running behind the scenes. I've even gotten ads popping up for Starbucks while flying in GO. Annoying.
I gave up on the Sammy's and took the recommendations on here and moved to an Apple iPad
Air 2 + Cellular with T-mobile (Should have gone with Verizon for more rural coverage around here, but live and learn.) and it is far above the Samsungs for video lag matters. Thankfully it hasn't demonstrated a lag matter yet, not even 1%, but I get a feeling that the iPad Pro model would be better from my chat with Autologic and using their Autoflight app which takes a lot of processing power against the
Air 2 once I begin to use it more.