I use this all the time with Unity based games which don't have borderless window as an explicit option in-game. Is there a way to use these from within the itch app, like Steam's "set launch options" functionality?

Edit: Oops, wrong subforum. Sorry!

Hey, sorry I missed you post. You can try using a manifest file to control command line arguments sent to the executable. This only available for developers though. https://itch.io/docs/itch/integrating/manifest.html

I don't think we have a way for people running the app to configure command line arguments right now