I was hoping to save these coins for a later date. Will they carry over to the next web and duck event?
No they wont
After any event the unused tokens become tokens for a stand alone store and stay there until you open them.
Only exception is Tacos which do roll over to the next taco vault.
I’m pretty sure the Vault aspect disappears too. So use the tokens now, I’d say. Also, this is apparently a one-off vault for introducing Rogue.
I believe they are still connected to a virtual, invisible vault that doesn’t deplete when you use the tokens. I know I have managed to get a legendary token from an inactive Taco vault. So if you save up the tokens and use them when the vault is inactive you might get more of the good stuff (you could, conceivably, get two Rogue covers), but the odds are much greater you will mostly get bad pulls since bad pulls don’t even deplete the vault anymore
So… do you feel lucky?