EZDome works fine in Poser 13.
I have been using it myself with no problem.
I have also converted the Poser 13 HDRI starting scenes to EZDome scenes.
Also, I get better shadows with EZDome - the Poser 13 shadow catcher is making shadows much sharper than the other shadows in the scene.

Still, the Poser 13 shadow catcher is much easier to use than EZDome, so that's a good thing.

Free stuff @ https://poser.cobrablade.net/