Rested xp accumulation

Okay, not a new player, but this is very much a noob question that I just never got answered. I've searched everywhere, and gotten nothing but conflicting and incomplete info, so I'm hoping I can get a definitive response here.

What affects the rate of rest XP accumulation? Like, logging off in a sanctuary is better than logging off in the wild, but are there any tiers above that? Are cities better than sanctuary towns? Are residential districts or houses any better? Is there any benefit at all to logging off in an Inn room?

I'm pretty sure it's an all or nothing thing. Either you're in a sanctuary and get rest XP or you're not and don't. I don't think there are any different tiers in how fast it accumulates.

(When the game first released, there was an advantage to logging out at the inn because the main cities were not at the time treated as sanctuaries, except within the Inn. You got rest XP if you logged out at the inn or around an outpost's Aetherite. But it didn't really make a lot of sense why the outposts were safer than the cities, so they changed it to make the entirety of each of the main cities act as Sanctuary. Since that change, it hasn't really mattered if you go to the Inn or not. I still normally do, but that's mostly an immersion thing.)

It used to be you only gained rest xp if you logged off in the inn room. They changed that fairly early on, and now you gain rest xp simply by being in a 'sanctuary' area (usually a town).

There's no difference in the amount of rest xp gained. It seems to be simply coded in to the effect of sanctuary (along with changing skills/classes without cooldown)