no noctis filter.
If anyone has left and returned, they've not been forthcoming with any details.
In terms of how people arrive and leave, I can give you a vague theory? With the caveat that it's maybe 80% speculation.
An awful lot of the native mythology (gleaned from our connections to the local covens and an assessment of what historical materials the DOA were able to secure us access to) centres around the concept that Everything Stems From, And Ultimately Returns To, Vallo Itself. The one time we've tried prodding a Waypoint to see what was behind it, we came away with the impression that there's a sentience tied to the ebb and flow, but one that's vast and alien and either not interested in talking or unable to communicate in a way we tiny specks living on its surface can understand. So the theory is that its cycle is overflowing this... world state? Reality? Whatever you want to call it, and pulling in things from Elsewhere.
Not entirely sure what use that information is, but there you go.
If you've ideas for where to go next, let's talk. I can point you at people with similar interests and try and secure whatever funding and resources you're after, with the understanding that a lot of people are quite happy here and don't want us Magical Research Sorts threatening that.