Custom icons in Folder-Tabs?

How can I show custom icons in Folder-Tabs?

I don't "think" you can lock a tab to show a particular icon... but I seem to recall the tab should inherit the icon of the folder being displayed? But that's not working here for me in a quick test...

There's a known issue (LD#01027) where folder tabs don't show custom icons for folders that have them set via Properties/Customize.