Just in case anyone needs that, here's a way to get it:
- Download and install Borderless Gaming from https://github.com/Codeusa/Borderless-Gaming/releases
- Add fba, by window title, with a regular expression. Use this for regular fba builds: FB\sAlpha\sv\d\.\d\.\d{1,2}\.\d{1,2}\s?\s[^\[].*
- right-click on the fba window to get the menu-less window