In reply to Tai.

@Tai: Thanks very much for identifying these areas for improvement.

The mobile icons acquired the Collapse footer. That was prime real estate.

What did you have in mind that should have been located here? I'll also note that the word “Collapse” is redundant with the left-arrow button to collapse the sidebar, so we would have some additional space if we hid that text.

Some Active Callbacks seem finicky at times.

Do you have an example of this?

No core rgba color control.

Are you saying you want an alternative to entering a HEX color, the ability to toggle between HEX, RGB, and even HSL (similar to Chrome's dev tools)? Seems like a good enhancement ticket.

Multi-click panels. No panel/section cursor click-backs (clicking Static Front Page, mouse has to go all the way back to top).

Good point. This has been raised in #35186. Please watch that ticket.

Depending on a theme’s nav walker, clicking through Live Preview links can be sluggish and the beforeSend or refresh indicator gives awkward state indication.

Could you elaborate on this? File a ticket?

Sometimes Change theme panel, while in scroll gets stuck and can’t go back up. Sidebar is too wide.

Yes, there are definitely issues with the positioning of the panels and the animations between them. Please watch #34391.