Well in the description for the DVD version of the UCE it says, "Includes a special "wraparound" version that replicates the original Cinerama theatrical experience." So looks like we're getting it too!
It looks like that's been addressed. Look closely at the before/after screenshots. It seems the angles of the panels have been horizontally corrected. And they haven't erased the lines, but aligned the panes without any visible join lines.
You can see an example of smilebox here: The Cinerama Adventure - "Smilebox" Process By the way, this 93-minute doc is included so yay! But like I said before, hopefully there will be a good restoration feature on HWWW too.