I definitely agree.
it's fascinating to give a sequential listen to the R&H era demo, The Lovetown cover of All Along the Watchtower, the Berlin Recordings, the Popmart outro of Last Night on Earth, and the Thomas and Lillywhite versions of All Because of You.
They were definitely trying to distill that certain vibe of a stomping rock-groove but it took them some time to get there, I think the live version LNOE was an important step towards it.
I think that in many cases in U2's career the live versions of songs are an important springboard for writing new songs, because their not really a jam band, but toying with live renditions is where they challenge their ability to convey certain feelings and vibes as a playing ensemble in field conditions - the songs are often somehow different from the album versions, the reaction of the crowd to that is immediate and you can tell whether a band move is effective or not.
I wonder if their takes on Discotheque in the Chicago and Toronto Vertigo concerts took them anywhere on the new album...