Yeah the "authentication" can be super long. Sometimes you are connected to the server and get to see your future team getting wrecked 2v3 while you are authenticating.

Not a big deal since it's mostly an issue in casual but annoying nonetheless.

I'll be honest I expected them to fully block linux via the EasyAnticheat but they didn't. So for now it remains functional but on UE6 and new code they might try to dump the linux support.

I haven't played it in awhile, but it also ran great on my steam deck through heroic

For me, when I load the game, sometimes at the title screen, but more frequently only when I start a competitive game, the entire screen starts flashing black and then back to the game maybe once or twice a second. It often settles down after a minute and stops flashing, but sometimes it starts flashing again or it won't stop for the entire game. And then, sometimes, the entire screen turns black and stays black and I have to restart the game to get the graphics to return.