Just buy the flare x then mate is my advice.
If you're going to upgrade to 4x16gb in the future you'll be definitely limited to 2400 ram speeds .
Ignore the qvl lists mate honestly , that flare x is Samsung b-die for certain.
You are not going to have any compatibility issues with it at all .
My board recommendations on the other thread still stand.
I own the pro 4 myself , it doesn't look fancy but it's just rock solid quality wise.