Hello everyone,
The dark mode styling issues should be fixed in 1.2.9.9.3.
As for the other issues that concern the toolbar overlapping header content, it seems like the Gutenberg team have a fix for this, although I do believe this won’t be released before WordPress 6.3.1.
We have added a small fix for the width of the toolbar that should not hide the responsive actions.
I will be leaving this bug opened and confirmed, although it is currently out of our control.
Cheers,