This is how I fullscreen

[Riiyan]

I run the game at 1280x960 and fullscreen into 1440, on windows 10 base titanium build. This theoretically should work for all variations of resolutions without the need to use other tools to get proper fullscreen. Some might look like shit though. Ok here are the settings, going to provide NVidia, can do the same thing on AMD you just apply the method.

Apply your resolutions you are using to match how I use it for my resolutions and set all the settings exactly as this.

https://i.ibb.co/HrZ1MkH/scaling.png

Go to to your shortcut and change all the settings to match this, go into change HIGH DPI Settings and uncheck the top box. Leave the bottom checked and on application.

https://i.ibb.co/PFFZCrT/scaling1.png

Your game should now properly scale and have no click through in fullscreen and alt tab should now work properly, if it doesn't you need to start with a fresh ini file and attempt again, these settings verified work on 4 separate machines I have.

[Riiyan]

I see a lot of people complain about fullscreen and the work around is usually not vanilla in nature, this is probably the closes you can get to a vanilla fullscreen workaround for fullscreen. It also lets you control your UI size some because different resolutions scale into larger or smaller button surfaces and UI elements. Felt like I had to speak up knowing I use this easy method and it works rather well, the switching in and out is slow, but hey, so was classics alt tab. Anyways, good look everyone!