Update:
Okay, I cannot stand it when something isn't working and I had some free time today so I decided to experiment a bit further. First off, I backed up my OS so I had an easy way to revert to a working state. I now installed the "Common Updater." It ran, and as far as I could tell it changed nothing. The package had the same contents, no new paper profiles and still printed as normal. So far so good.
Next I held my breath and loaded the new driver. It ran. Interesting note is after I dragged the disk image to the trash, the trash wouldn't empty as some EFP module is still being used. I had noticed this before and can confirm a computer restart clears whatever it is -- but it is disturbing. Anyway, I can confirm this does indeed add the newest paper profiles. Best part is I could still print normally AND the UI is present just as it was in prior form. Comforting.
So I bit my lip and ran the Remote Panel update. This also ran normally, and added an App icon shortcut to the desktop. I confirmed this was the same app as loaded in the remote panel 2 package. Best part, the printer prints normally, at least as far as I can tell. So success!
Conclusion: All I can assume is the Common Updater has to be installed for everything down the line to work properly.
One other FWIW. I use Epson's Exhibition Fine Art paper on occasion. The current Epson stand alone profile for it is very good, but requires you to use to create a custom media choice using Epson's PPP Luster paper and set up an increased ink density of +12% under advanced media control. I have obviously done that and results are excellent. However, now that paper is a media choice in the driver, we no longer need that -- at least I assume that, but have not printed a test print on it yet to confirm -- so just a head's up to modify that particular preset appropriately if you have one.