Not only is my favorite QoL the 5 second wait for simming Challenges (down from 5 minute wait), but I’ll go so far as to say it’s the single best thing that has happened to the game since Chewbacca wa...
For me it's between moving bronziums to the first slot in the store and giving us the option to sim GW. So many times I missed out on full prizes on GW because I didn't fight all the way through or forgot to refresh before the daily reset or something because it was becoming such a drag to play through all those matches, even though you could hit auto.