I don't know if this is possible to script. Maybe through another captain, but it would be cool to have randomly generated isles appear that players can investigate/explore.
I know there are probably one or two in the module, I think of that set isle for one, that players could go too!
Perhaps a scripted quest with a randomized element similar to the Mines, Garbage Pit, etc?
I can think of a certain quest that could be randomized into something similar. The problem still would be finding the rarely dropped component needed to take it and even then realizing what it was for.