I'd like to see a border-less canvass, or a blank canvass that is not tied to any specific screen size at the start.
It could work like this:
Start new project
In the settings, select blank canvass as the desired size
Create what you want in an infinite canvass
Select the "Export Persona"
Select the screen/print draw size (when drawn onto the canvass, it would be a box with dotted borders by default with the screen size stapled to the bottom of that dotted box (1920 X 1080 for example))
Group what every you want under that screen/print size layer
Export that screen/print size layer with all children and it will export it to the pre-set box size
I think this would be an effective way to have one canvass with every piece of the project floating in it, then you can export what you like at any screen size you like utilizing the Export Persona.