Actually it's kinda funny, but if you take a closer look at the way Edge treats their back catalogue you'll notice that many songs, for the first couple of tours played live (or maybe from the second tour onwards) will get a rather progressive and innovative treatment, taking them quite further from the album version in terms of arrangement, then after about a decade, or when they return to the setlist after a long hiatus, will receive a conservative treatment on Edge's part and a sound and an arrangement closer to the album version, this is true for Mysterious Ways, BTBS (they keep changing the end, but I guess it's more Bono-induced, as it has to suit his additions, the Verse-Chorus-Verse-Chorus have been getting closer than ever to the JT version on the Elevation and Vertigo tours), The fly has actually come closer to the ZooTV version and Hansa demos on the Vertigo tour, appart from its intro it had that organic sound quite removed from the contrast between dreamy and industrial direction that brought it to an extreme on the elevation tour. I just think that when it comes to Edge, as years go by he usually gets to feel more confident about the parts he played on the album or the way they played the song first in the studio, the current guitar parts on UV is pretty much what you can hear him play on Achtung, so I think its true for most songs that don't end up as acoustic versions.
I think bono once said something like "I would love to do a new arrangement for One, but the presbyterian Edge and the Teutonic Larry Mullen go 'No, it's gonna stay right where it is', Edge will say 'it's a guitar melody, I can't change the melody to a song'".
Adam is the one that likes to kick things around. listen to his melodic leads on Streets, and his offbeat punches on SBS right after the solo, It's getting raggae!