From CRT days I know I can see 60hz but not 75hz. I had stupidly assumed that modern 60hz with freesync would be ok. It's not. Especially @ grey colour for some reason (Asus screen).
The fact that I was coming from a 120hz laptop screen didn't help the situation either.
Anyway...so I'm buying a 144hz 1440p gaming screen next. Screw this resolution game...I need flicker free for my sanity.