Just goes to show...I develop in a Jobo so I just read a book until the timer goes off, and I standardized on 75F because my Jobo will heat but not cool and my ambient temperatures are near 75 in the summer anyway (occasionally more like 76.) So this would never have occurred to me.
When I saw the title of the thread I was wondering if it might be about pushability. One of the things I liked about Plus-X was how well it responded to Diafine. I liked Plus-X at 400 in Diafine better in some respects than Tri-X at box speed in normal developers.