I'll give this a shot. Zest heavily dependent on GEF, and although
there are some signficiant places where GEF behvavior does no
completely match up, there is a lot of API overlap. What things more
specifically are you having issues with?
Recently they added the ability to use figure providers whihc has been
hugely useful for me.
It definetly it would be super nice to be able to use the Zest Layout
algorithms as regular layout managers.