"Either that or after the restart you could appear where you were with all the monsters in the same state or at least the beginning of the current depth."

The monsters in the same state is very hard to do, since the server would have to save state entirely, rather than just key elements. While certainly feasible its not really cost/time effective from a development stand point.

At the beginning of the current depth is completely NOT an option because it would be abusable. I.e. if you were at Vanaduke and the 30 minute warning popped up, you could kill him receive loot etc, and then simply wait for the restart while there, and kill him again at 0CE cost.

I totally hear ya about earlier warnings though.

As a software developer, I wouldn't assume that total state saving is hard. It depends entirely on how they built the engine, so I generally leave it up to the devs to determine if something is feasible or worth the development time. As an example, I had once written a multi-step configuration wizard, and the team lead asked me to break it apart into a series of pop-up dialogs. The other people on my team hand-wired all their user interfaces, so they would have had to break apart all their code, reorganize it, graft it into dialog boxes, and add code so each dialog box knew what had been chosen in earlier ones. It would have been a major rewrite. My code was much cleaner, so I was done in five minutes and my tweak was reusable so it would take a single line of code if I needed to do it to a different wizard in the future. If it's organized right, saving and restoring state could be trivial.