Well, I tested the script on the newest version of the game, I only used the part to change character levels. It seems to work fine, however characters assigned to tasks in HQ don't get leveled up, but that's not much of a problem.
HOWEVER, I did encounter a somewhat weird bug. After I changed the levels of my characters (set them to 23, which is my current brotherhood level), the Ranking in current Rift Event stopped working, suddenly I'm the only one in my level bracket and I'm shown as 1st. Not sure what happened there.