I received my new fold 3 yesterday from Vodafone. First start was without sim card because I use esim only. My csc is stuck at EUX I have no volte or WiFi calling option in my phone settings.
I have done the CSC change using Samkey 1 week ago by buying 2 keys on eBay.
Sadly it didn't work for me, I guess the reason is that I don't have a multi CSC device. I was on eux and still am. So I can't answer your first question. No, it doesn't wipe your storage.
I think I'll stay on EUX as well since Google Pay works. I would have liked for Samsung Pay to be working as well as I got rather used to it on my Note 10+ I sort of preferred it over Google Pay but hey. Samsung shouldn't be locking Pay based on CSC it should work as long as Samsung Pay is available for your bank and bank origin. (Which is how Google Pay works)
