So why not allow the choice of "Start in any lobby" instead of in a specific gate?
Someone might want to join a party, preferably one starting up, and which gate doesn't matter. So, from Moorcroft, join any depth 8 party lobby that people are starting up a party in.
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"Equally", why not allow people to start in the halfway lobbies as easily as in the starting lobby? Yes, there are some reasons not too -- it makes it easier to get to the next town. No different than joining a group partway there already. And joining at the crossroads seems far more logical than joining in the middle of a level.
So, I guess the suggestion is: Allow people the choice of:
Join any party lobby (recommended equipment: 0, 2, 4)
Join any crossroads (recommended equipment: 1, 3, 5)
Being able to quick join any gate would be a good idea. Right now you can check the population of each gate, but you still can't tell how many actually groups are there. I imagine they'll be improving this later on.