I never seem to upgrade DFW-BOS. Last summer I was close on BOS-DFW on a Friday evening flight but I got screwed over because I had a companion and they only released 1 seat at a time up till gate control (when only 1 seat remained). From T-100 till T-24, I saw 5 open F seats slowly disappear 1 at a time, and then at T-24 I could see I and companion were # 1 and 2, but from T-24 till gate control, I saw the #3 disappear on the list three different times whenever an F seat opened up and then disappeared -- I was perhaps a little obsessed that morning watching it so closely, but I am a bit peaved on how AA's system keeps filling 1 seat at a time. In hindsight, my upgrade chances with a companion are near nothing (happened once? DFW-SEA in Fall of 2020) but my upgrades traveling solo the last 2 years has been about 50%. Always going through DFW, but usually I travel at non-elite-peak times. Anyways, side-story - but I find the companion upgrade perk to be trash, I haven't even gotten domestic upgrades on SWUs when I have a companion if it wasn't cleared at booking -- Companions really just likely ruins your own upgrade.