This looks great - the theme editor in Godot is a great tool once you figure out how to use it.

I just wrote a scaling script to find the difference between a target resolution in my case 1080p and whatever resolution you are currently using and then I have it find the proportionality between the two in order to scale.

That way I can just lay out my UI however I want it will always be the same size regardless of the resolution.

It really lets you focus on art woth the theme editor instead of messing around with columns and rows.