This is honestly the most annoying bug in the software. Any time you create a custom resolution at 4:3, you have NO OPTION to maintain aspect ratio. It's complete crap. The driver always decides to stretch full screen.
Please make this the #1 thing to fix. Make it so we can MAINTAIN ASPECT RATIO for custom resolutions.
I'm purposely bumping all aspect ratio questions so you programmers know how serious of an issue this is.
Also fix the limited 60hz problem for monitors that can go to 120hz. That's another huge bug.