I made the fullscreen default to on in the latest daily build.

If you already accessed the options screen and hit ok (and thus the fullscreen selection was set to false in the config file) and want the default to be fullscreen on you can just go into the options screen and check "fullscreen" and hit ok.

Same with the aspect ratio correction checkbox.

Remember that the settings are stored in ~/.scummvmrc and so uninstall/reinstall does not purge your settings (which includes game entry list)