I don’t entirety understand what you are asking me, but I can explain in detail how my system now works with Epic own system.
When a packaged game is started the engine reads the GameUserSettings.ini file, applies its settings and starts the game with its resolution and screen mode.
If no GameUserSettings.ini is found. It uses a default one with windowed fullscreen with your systems max resolution. (As far as I have observed)
If the game is started in a fullscreen mode from GameUserSettings.ini file or default settings, it is now in the bugged state where the game will be stuck in corner and missing a titlebar if screen mode is changed to windowed.
When the game has started, my system takes over. First it loads its own file “SettingsSaveFile.sav” or creates a new one if none is found.
Then it reads the data from ini file that epic has made available through blueprints. It replaces the relevant variables in my settings system, such as quality settings, resolution and screen mode.
Some settings, like motion blur, brightness and keybinding are stored in SettingsSaveFile.sav and is not affected by the GameUserSettings.ini
When my settings system later applies settings, it mostly ignores the settings system Epic included with 4.11, and uses the “execute console command” node instead, since it is more flexible and can have more features.
The exception is when it applies resolutions. Here I now use Epics own system to apply resolution settings. I thought this fixed the windowed issue, but it didn’t, and that’s when I bug reported it to epic. Using the old console command “r.SetRes {XRes}x{YRes}{Mode}” does not improve this problem. (It worked in previous engine releases)
When the player press OK to save the settings file, it then does the reverse, and copies settings from my system, to epics system, to properly store settings in the GameUserSettings.ini file. The ini file is then saved before “SettingsSaveFile.sav” is saved.
So Epics system is partially merged, but not fully used due to lack of flexibility. I mostly only have it now for the ini file since a user requested it. I’ll improve it whenever I can.
The idea I will try out later is to set GameUserSettings.ini to always start the game in window mode, (to avoid bugged state), then instantly on gamestart change screenmode according to my SettingsSaveFile.sav and not GameUserSettings.ini
Hopefully this can “fix” the the windowed problem.
I’ll tell you later if this works or not.