This is my first upgrade, I started using TrueNAS on 24.04.1 around July this year. Anyway I had a bit of a puckered sphincter as I hit the update button to 24.10 because I am using a combined boot/apps NVMe drive so I thought maybe the update would crash, pleasantly it did not.
I should note however that I am not using TrueNAS app system. I have a Gaol (Jail for you Americans) and I was already running my own docker apps within it, and it was unaffected by the upgrade so happy days.
Figured I would share my experience.