gnome-shell has a feature that appears to automatically maximise new windows that are presented with a size near the full size of the screen.  This feature really doesn't makes sense on "normal computers" so we should probably try to disable it for that case (probably including laptops).

At the very least, this needs a GSettings key and a checkbox in the tweak tool but, really, this is probably something that should only ever be enabled by default for tablet-type cases in the first place.