Hi @robertag
The sizes are dynamic and can be controlled right from the Customiser -> General -> Layout section.
For example, when everything is set to boxed, the Max Site Width option forces everything to that specific size — https://streamable.com/saqkpx
The normal view is still controlled by that, but it doesn’t get a boxed type of view and spans its background across.
The full width view simply extends everything to around 98vw.
Hope this helps!
Thanks.