I have a minor problem with latte dock compiled from the git repo. Some Active Window Control plasmoid settings ("Hide titlebar for maximized windows" in particular) are not persisted, it will always turn back to the "off" state on the next launch of latte-dock. Oddly enough it doesn't seem to happen on current version available at Arch Linux/Manjaro repository right now. I will provide more info if needed.
Latte supports multiple layouts at the same time so borderless maximized windows has become an internal Latte feature. 1. Disable borderless maximized windows in Active Window Control 2. Latte Settings window (you can use Meta+W) -> Preferences (tab) -> Support borderless maximized windows in different layouts 3. Latte Settings window -> Layouts (tab) -> just enabled the Borderless feature at the layout you want