I think I read somewhere that stated older EZdome scenes wouldn't work correctly in P13.

Not sure how accurate that is, I never used EZdome, so just saying, it might save you frustration trying to get it to work.

What I've been doing is just use the widestreet scene and replace the default HDR in it with different sky HDRs from poly haven and a couple other places.

Those two scenes have an environment prop that doesn't exist in the default "alternate construct" scene, and I'm not sure if there's a way to add it.

So maybe you could try taking the backgrounds from your EZdome scene (if they're HDR) and using that in place of the wide street or beach scenes.

You would have to of course merge all the other content from those scenes into the new one.

You can also create your own HDRs in blender and use those, at least in theory. I haven't tried it yet but saw a video on it a few days back.

I'm still trying to figure all this out too so these are just things I would try doing myself, grain of salt and all that.

Would be nice if we had an official webinar on how to use all these new features and what their limitations are etc., but a month in and crickets.