I found a vault ticket in my inventory. I used it and I get 3 Flawless Nth Metals which is 3000 XP which is about the same we used to get from the vault on a weekly basis. Would you buy a vault ticket each week with the 3000 artifact XP for your unused Fate Tokens?
At this point, if they added anything of remote value on the Dr. Fate vendor for Fate Tokens, I'd buy them. I scoop up the stabilizer and nth metal detectors first thing after reset.
SIDE NOTE: if you ever find any more, save it for 2x drop week. The drops double too. It's toon bound unfortunately, but yeah...a lot. I found a toon that had 36 of them a ways back and opened them on 2x week. That toon was a happy camper for sure.
No, I would not since the vault is only available during the Seasonal Events. I would strongly consider using Fate Tokens instead of Replay Badges to reset the seasonal vault if that option was available.
Queueing in to the vault is seasonal, correct. But you can use your vault ticket anytime even if its not available to queue in. When you do that, you get all the loot that you would've gotten immediately after using the ticket.
This is true because the vault tickets are granting what you would have gotten with the old vault system. If you still have vault tickets on your characters, you can choose to use them or keep them as the devs got rid of them. I dont think the devs will bring back vault tickets any time soon, if ever, because they made the seasonal vault RNG more generous and the loot more valuable; that entices players to use replay badges (which generates more profits than vault tickets) to re-run it.