I don't mind Know Your Enemy, I liked it better 2nd or 3rd in the set but not sure as an opener. And it's better when it's just played through, not when it's drug out in the middle. There are other songs I'd rather hear off of 21CB first. Also realizing that in addition to only one song off 21CB, no songs off any of the trilogy albums. Just because they didn't tour as extensively on that, there are a couple I'd want to hear.
Post-AI songs that would go down a treat in concert: 21st Century Breakdown East Jesus Nowhere Stay The Night Stray Heart X Kid 99 Revolutions I think they picked the right songs from Revolution Radio, although I'd throw Too Dumb to Die in there. Forever Now is an absolute jam.