How to get Godot editor to use specified viewport width?

Godot Version

4.5.1

Question

I’m struggling with trying to change my project’s viewport size for a mobile variation of a game I’m working on. I’m using the settings customizations to create different viewport sizes for pc an mobile. Unfortunately, if I set the Viewiport Width.pc, it overrides the default Vieport Width.

I want to be able to design the screens that will run on mobile, so I want the viewport width to be 720 for now, but if I add the Viewport Width.pc as 1920, this overrides the Viewport Width in the editor and when I edit in 2D mode the workspace is 1920 wide, not 720. The only way to edit with a width of 720 is to delete the Viewport Width.pc entry.

Is there a work around for this so I don’t need to keep deleting this value?