Yes sir there is much to be said for increasing non foul lean angle. Lowering the rear does not decrease lean clearance nearly as much as lowering the front.
Unless modifying engine significantly and intentions to really press limits, 19" on both ends is more pleasant and fun to me. Going by some hints of road riders reports and my own findings, I'm reducing hot rod Peel front tire to 100/90x19".
I've got two rear wheels on hand for factory Combat Trixie, one 19" one 18". That way can ride again sooner for tire repair issues and use up any size tires I find bargains on. The main issue on same day switching, is on crossing my cattle grate drive way exit, for first real lean with power enough to climb slope onto Gravel road way, can't get quite as spunky on 19" 110 as can on 18" 120 before squealing to recover the over sight.