there's two answers to this question, one is mechanical and one is social. you as the DM can tell the players no not now, and they can't do anything about it, but that doesn't mean they won't try to do something about it, which depending on the group could be an issue.
so in this scenario a good DM could whip up some misdirection, for example set up a traveling artificer who just passed through town a couple weeks back and who the players could track down as a lead - conveniently in the direction of the main quest objective.
you're definitely right about the time limit. at that point you are about 5 minutes away from every spell in the party's arsenal being cast on that crown, followed by the main quest getting derailed by the mystery of the plot armored artifact.
i remember going home with a friend because my parents were both working, and watching him play team fortress classic while half the lobby had nicknames like "OSAMA BIN LADEN HAS NO BALLS"
2049 is great. i think he's a cringey prick but if jared leto's screen presence can't kill fight club, american psycho, or requiem for a dream, he definitely can't kill blade runner.
i know lots of people prefer the original (and of course it's by far more influential) but you're the first i've seen call it a disgrace.
i guess i'm the only one really excited for this? i already play elden ring randomizer runs for fun and this offers a lot more variety than that. i am very interested in seeing what they can accomplish in a new formula.
i couldn't get through two episodes as a huge fan of the manga. it was a total letdown.