Windowed Size?

First thing I would like to say I’m really amazed with the functionality of the porting and I can only hope more Halo content will follow on PC.

Then I would simply give a small complaint with the video settings: my native resolution (1920x1080) is quite big for my poor graphic card so when a game is too demanding (like Halo) I prefer to play windowed at a smaller res for a boost in my fps. This works extremely well also when I want to stream, so that instead of streaming my whole screen I just stream a smaller 1280x720 window.

My issue is simple: the windowed mode doesn’t scale automatically to the chosen resolution. I have to manually attempt to resize the borders correctly, which ends up with a blurred image because of the rendering mismatch.
Is there any way to set the window size locked to the resolution? Or at least give the window the correct size? I tried searching for the game config files but apparently they cannot be edited (-Yoink- encoding).

Any help would be appreciated ^-^