I wanted to request the feature similar to what Nvidia has known as "Preferred refresh rate". With Nvidia, you can choose either "Application controlled" or "Highest available". This should be able to be set globally or on a per-game basis.
On top of that, I think it would be useful if you could also choose a specific refresh rates from the drop down as well.
Too many games don't let you choose what refresh rate to run at, so even if I choose 1440p instead of 4K, it will auto select 60hz instead of the 120hz I have available at 1440p. Instead I have to force Win 10 desktop to 1440p, then goto monitor display settings, and force desktop to 120hz. Then relaunch the game I want to run at 120hz. What a terrible annoyance. I play some games at 4k60hz and some at 1440p120hz. Switching between them right now on HDMI is a pain.