Add individual css class to default block variations (by default)

[hanneslsm]

When blocks have style variations, the default should have a corresponding css class.

Use case:
I want to add a text-shadow to my default button (but only this one).
I cannot do it via theme.json "css": "text-shadow…" because this adds it also to the outline and other custom variations. At the moment it's not possible to use "css":… in variations to remove this css then again.
Therefore, I must enqueue a css file.
However, I cannot only target the default button, because it does not have by default an individual css class. Only after I have clicked on the style variation "default" the css class is-style-fill is added. (By the way, it could make sense to rename this to default, instead of fill)

There is probably somewhere a discussion around this already, but I couldn't find it. If anyone knows where it was, it'd love to know the reason why this isn't implemented yet.

[cbirdsong]

The way I've handled this is adding extra awkward CSS selectors:

.wp-block-button:not([class*="is-style-"]) > .wp-block-button__link, 
.wp-block-button.is-style-fill > .wp-block-button__link {
  // styles here
}

It would make a lot more sense if there was a simple "reset" behavior to get back to the default. (see also #55258, #47976)

[hanneslsm]

Genius, Thanks!
You're linked issues are very much needed!