What happens if I exceed 4 passengers?

[Phlagm]

I think it probably just unceremoniously fails at some point. Some overflows are handled gracefully, but some aren't. Generally, they just cause crashes....often at a point when you can't tell what the hell happened

My future solution to the above problem would be to do the complicated KEYS thing, but just make it complicated enough to break the predictability (oh I got passenger X, that must mean I'll get totally unrelated quest Y) but maybe not so much as to completely randomize the thing. There are only 255 keywords allowed, after all.

It's a somewhat obnoxious challenge, because unless you do something with the Zorg or Muktians, those two passengers need always to be there. That leaves you two spots to play with.