Theme browser: Save user themes

I love your new theme browser but sometimes I want to use my own wallpaper (of my kids) or just have it on the lock screen.

It's currently possible to do this, to create a theme using a combination of wallpapers, clocks, anyicons, etc. But if we click to view another theme the one that we created is gone.

If I want to use a theme from the list but add my own wallpaper, the next time I load any other theme my wallpaper is gone.

I'd love the ability to save user themes.

I'd like to propose a more organised, capable theme browser for selecting Niagara created themes and user themes.

Bonus: This could enable dynamic (auto light/dark) themes, which I've seen other requests for.