Latte has been deprecated because its features are (afict) all now included in the base plasma panels.
You can make extra panels, have them float, have them dynamically change size, use panel colorizer to retheme only one (if desired).
On my ultraportable I've got a sidebar and a lower dock. The sidebar has actively running apps, my menu bar for open windows, a big honkin app launcher button, and my notification panel. My dock has all my frequently used apps, and some shortcuts to frequently used websites. All just minimal plasma-session + panel colorizer.

