For the first 2 weeks of a tier, to enter a raid we should need to be at the entrance

[PotatoTree]

I already get +15 min food duration from squadron scrolls and I get 10 scrolls per week at the cost of talking to my squadron manager once a week. Another +5min on top of that would be useless, as it won't change the number of foods I have to eat each raid instance.

Which is the point, I don't want to force you there if you don't want to be there, but give a tiny amount to someone on the fence about being there.

the deep dungeons require people to queue at the entrance and it is extremely difficult to find people to run them......

That doesn't really have anything to do with this mechanic though, that's just cause deep dungeon is not popular. And all raid content eventually becomes unpopular, which is why I propose a time cutoff of a few weeks, maybe a month, and then it becomes free-queue.

Perhaps a silly question, but: Normal, Savage, or both? Because I honestly don't see how this has any upsides for Normal. (I haven't raided Savage enough to have an informed opinion there.)

Imo just savage. Normal mode doers doing it the first time basically direct queue from the story without any prep anyway. But I didn't think this much into the actual details of the implementation.