I didn't exactly suggest to store it via auth even though I was thinking of something like that (But not really indepth as now xD).
There's an inherent problem with Metin2's auth where it is impossible to track someone after they teleport. There's no linking of one desc to the other, and db also receives a logoff. For all intents and purposes, a rewarp is almost like the player closed the client and logged back in (directly into their char that is). The second problem lies with passing around things on login: login is this continuous bouncing of packets and checks. Not fun to work with in my experience.
Nevertheless, you made it sound easy. If you know some existing way to keep track of the user (which I could have missed somehow!), please do tell!
However, as far as I'm aware, there are not too many options.
Way 1
Elevate -> notify db -> which notifies auth -> which stores IP and current timestamp.
Login, which goes through auth, checks if the player was already elevated (recently), and if the elevation was on the same IP, marks the user as elevated in the login.
The last part, well, I implemented a few things in login already, and I really don't like working with it much. But this way is definitely better than...
Way 2 (less painful, less clean as well)
Elevate -> Notify all P2P peers -> store it in some map again with IP and timestamp (Even maybe start an event that clears the map entry).
Login -> On PlayerLoad, check the map. Profit!
In your way 1 you're just taking a worthless step. Plus, auth shouldn't store nothing at all really, the auth core is only meant to Authenticate the user on login, and maybe send some of those hybrid keys, all the rest is done on db and game cores.
Your second option is the most logical one, and the best approach as well.