Hii!
So Twitch prefers streamers to go up to 3.5MB upload. reaching 3.6MB output irritates them to a point of the consideration of your ban. from past commentary on Twitch's behalf.
In my opinion 3MB - 3.5MB upload buffer looks okay to me. and adding downscale of 16 or 32 samples helps but that's like making your edges thicker.
so if you stream 1280x720 then your rendering is known as 720p (p = meaning progressive) so by default streamers flock to this resolution because that's what people usually watch it on when browsing it on PC. and this resolution is also downscaled more for smaller devices! unless you have viewers who have nothing to do on a 4K smart TV that happens to display Twitch via methods like Amazon Fire or Mini Desktops.
If you wanted more out of quality you can go to 1460x822 resolution output for streaming, and yes that's 822 progressive also known as 822p. that should add more detail but it also means it will delay display from what you see on your monitor to what later your viewers will see. (to shave off delay just lower stream to 30 FPS and 720 progressive. but you'll barely notice the benefit!)
I suppose you can go to Advanced OBS settings and look at YUV Color range and lower it to Partial to output standard colors, almost no one enables (Full) not even on Nvidia GPU preferences for their monitor display.
Hope I helped somewhat! you can also Whisper me on Twitch if you have question(s). Good luck!
