What problem does this address?

The current experience of managing styles in 6.5 feels great. The addition of the fonts library is incredible.
And it feels fantastic to customize every aspect of the theme typography, color and blocks.
Once we are done and happy, I find it sad that there is no real materialization of the effort.
We can't save and name our styles? And it is easy, mistakenly, to return to the base styles.
Even if there is this very good restore system, it feels like we never own our design.

Would it be a good addition to save the current state and be able to name it?

I did i like simulation (design is not perfect) but it tells the story:
See the figma prototype

Start from one of the existing styles

Edit name

The custom styles are marked