I have a script, to change refresh rate, monitor brightness, contrast and color settings with hotkeys, which I use often in different games to have the perfect screen settings for me.
When I change on of the mentioned settings, an AHK GUI shows me the new refresh rate, brightness, contrast and color levels.
However, this works only in direct3d games. There also work rainmeter skins with "always on top" option enabled.
In openGL games and UWP Apps like Minecraft Bedrock (the apps from windows store) it doesn't work. The AHK GUI an rainmeter skins are not visible. It seems, that when openGL and UWP are in fullscreen, you can't draw another thing on top.
But is there really no way? The steam and RTSS overlay from MSI afterburner are visible and over the openGL and UWP Window, so technically it should be possible.