Adding the option to set dynamic additional classes, in addition to the dropdown list of existing classes.
Existing classes, option to set new classes and dynamic classes should work together with no restrictions.
The original thought was to control classes dynamically (via ACF, etc.).
Just like it’s currently possible with the dynamic attribute option.
So it’s about getting access to a class field without necessarily having (direct) access to a class field.
Maybe as a dedicated option besides block, virtual and global classes.
Maybe as an additional option for virtual and global classes.
Not sure what would be the way to go or what makes most sense.
Use cases would be templates, global parts, queries, repeaters, etc.
But also to control styling (properly with classes) from backend via ACF only.
Hope it’s fine that I answered here on behalf.
It was my suggestion (at least I’m pretty sure), so I thought I could reproduce it in a proper way.
Not sure I quite understand where virtual classes are breaking.
If you mean that you cannot use a block class on another page, this is indeed by design and was introduced as a breaking change since we prefer relying on global classes if you want to spread controlled classes throughout multiple pages.
I think the interest of dynamic virtual classes here is to be able to style elements either through ACF fields or with conditions that you wouldn’t necessarily be able to apply as easily with the current toolset.