Get five electricians to look at something and you may come up with five different ways to do it. All of them probably right. So, I'll take a go at it.
I would have put the new meter can in the same place as the old one thus saving the need for cutting the roofing tile for a new hole. Of course you would adjust the height. The new panel would have had the left side exposed for conduit and that would have eliminated the need for the Carlon. As far as I know RT panels don't come with knockouts in the top. They come with one hub so, just a guess, you had to knockout three holes in the top of the can. That's something you want to avoid. But you are in AZ and the climate is not like here in FL. If the wires ran a bit short a PVC box would have given you some relief and maybe allowed for a combined raceway to the panel. That timer in the lower left could have been swung out of the way adding some room for the new stuff.
As with all things one doesn't really know what's going on unless they are physically there.