I don't see any reason to drop songs from the set, I would like him to use his voice as much as possible during the set. I use the songs he is not that good in, to compare them to earlier performances, and eventually state if he improved his singing or not. Faint bridge and ending/last chorus, ND, Numb bridge, Crawling, BIO ending, WY bridge and GU is the ones he struggles most with. He already saves his voice by letting crowd sing Numb bridge, WY bridge etc. I think he should visit a doctor or something, to let him know what should he do to save his voice. I would recommend him to stop smoking (if he still does). I think LP should shorten their set, but keep it more intensive. Another thing they should do, is rotating songs, to play many songs that hasn't been played because of shorter set, it would also make their shows more entertaining.
He said that LP songs is the hardest ones for him to sing.