@Avactersits not down to a pack, they just have to be changed by clicking Change Outfit on the Sim. They don't change automatically. Even when my Sims are going home from Sulani they arrive on the doorstep in their swimwear if they have to swim to leave an island.
It would possibly annoy players if it happened automatically because if they were having a day at the beach or sunbathing, or in and out of the pool they'd need to keep their costume on. Just click on them to change and with school I'd just check what time their class is so that they have time to do a quick change and don't walk into class in their swimwear as that would be quite annoying.
But sometimes queuing Change Outfit still works even if they are busy, but I don't know if it works in class. It does work over some tasks like talking and eating though.
I did have a big problem with Sims leaving the Mt Komorebi onsen bath house and going on a group hike in swimwear! None of the NPCs got changed and my Sim was the only one dressed for the snow!
I realized I just likely had a mod before the pack, that automatically changed their clothes through laundry day and I guess cause I don’t have it anymore the alot of changing clothes kicked in.
the issue was is that my sims use to change out of their wet clothes I automatically after swimming or getting wet in the rain it was a mod at the time and I’m don’t have it anymore so yeah haha
