I've been using customized page-layouts in my Hubzilla theme(s). But I really wonder, how much people use the native Hubzilla page editor at /pdledit to really make the channel "their own" by moving things around.
To use the templates which come with the (my) theme(s), one would have to "reset" a previously customized page-layout (or go for the copy & paste route) to only include/replace parts of it.
It's a fantastic option for deep customization of your whole own Hubzilla experience, but it might appear a bit "hard" to understand at first... (The editor as such needs to be (App)installed by your admin!)
Just "vote" yes, if you are familiar/using the functionality. (Or comment below.)