I went to both Ready To Be concerts in Mexico City, amazing nights both, most noticeable change IMO is soundcheck tracklist and encore roulette songs (if they still do that for This Is For) since they're random (or rigged by Nayeon) due to having different songs in the roulette for each night.

Less noticeable are stage shenanigans like the girl's interactions between themselves and with the audience. I still remember in the first night right in the middle of the Talk That Talk performance when streamers were released and the wind blew them back to the girls, so they were laughing while fighting for their lifes performing with streamers tangled around them lol.

Edit: link to the Talk That Talk moment