Windows 10: How to verify Fullscreen Optimizations feature is off?!

Hello,

i check "disable Fullscreen Optimizations" in combatibility tab, yet i read it is not working from build 1703! I also tried some registry entries. Problem is how do i verify it is off?! From microsoft dev blog: when fullscreen optimizations feature is on, screen flickers in PC games! Which is what is happening, it is only when they are loading. But problem is, that it can mean Fullscreen Optimizations feature is on!

How do i verify this is off and in case it is on how do i turn this off?! Microsoft support doesn't even read what you say...

This feature is terrible and causing lag and fps drops!

:)

 

Can't disable 'Fullscreen optimizations' globally after October 1809 update

I have always disabled Windows 10's Fullscreen optimizations. Even if some people say the new 'fullscreen' presentation mode offers better performance and quicker alt-tabbing, I still disable it. I have my reasons. I want all of my games to run in
Exclusive fullscreen mode. And for me, the registry entry, 'GameDVR_FSEBehavior' set to '2' always disabled Fullscreen optimizations globally (no need to go into each .exe's Compatibility settings to disable it).
Located in: HKEY_CURRENT_USER\System\GameConfigStore

Now, after the 1809 October feature update. The fullscreen optimizations presentation mode defaults to on in all games, regardless of the 'GameDVR_FSEBehavior' value. The other method of disabling it globally has also been gone for a few months now. Unchecking
the box, "Show game bar when I play full-screen games Microsoft has verified" used to disable Fullscreen optmizations globally, but that setting was removed from the Gaming options in Windows.

I would like to know how to disable the Fullscreen optmizations presentation mode
globally in Windows 10 after the October 2018 update.

I do realize that individual .exe's can disable Fullscreen optimizations by right-clicking, Properties, and going to Compatibility tab, but even this solution doesn't work for all games now.
For example; after the October update, I have yet to find a way to disable fullscreen optimizations for Fortnite BR. Even with the option checked in the exe, it still runs in the 'enhanced fullscreen' mode. I cannot find a way to run Fortnite
BR in exclusive fullscreen after the October update 1809.

Thanks!

 

What exactly is FullScreen Optimization in Creator's Update?

I was not able to find any documentation or description, official or unofficial, on what the "fullscreen optimization" really does?

It turns "true" fullscreen mode into a hybrid Borderless Windowed mode.

With certain games it is recommended to disable fullscreen optimization. Some reports better FPS, reduced input lag, but the results vary per game, probably per configuration.

Sources:

1. Why you should disable Fullscreen Optimizations on Windows 10
   
2. What exactly is FullScreen Optimization in Creator's Update?
   
3. Windows 10 forces games into a faux fullscreen that is actually more like windows borderless and may seriously lower performance. fix inside : pcgaming
   

 

Can Fullscreen optimization cause input lag?

I've heard some games like Overwatch and CSGO can have some lag input when fullscreen optimization is enabled. Can you tell me what Fullscreen optimization actually does?