Problems I noticed with windowed/borderless modes:

Resolution Issue

I am using dual 4K monitors and I want to run the game on 1080p borderless window mode so that I can seamlessly use my second monitor. The way to do this on every other game is simple: You choose borderless window mode and lower the resolution. But whenever I lower the resolution to 1080p in Apex the window doesn't scale to cover the full screen. Instead, it gets smaller with the resolution. The only solution I was able to find is lowering the resolution of my display to 1080p through windows settings(making everything blurrier.). 

Performance Issue

The problem with the above-mentioned solution is that I get 1/4 of the fps I should be getting. I am playing on lowest settings with a GTX 1080 and I am getting 60fps at best seeing below 40 during fights. When I scrap that and play the game on full screen mode which renders my second screen useless I get 150+ fps

Can anyone recommend something or is this a known issue waiting to be fixed?