Give us the ability to unlock the mutated versions of the expeditions that arent currently in the rotation for that week.
Give us a questing system like the faction quests that give us the ability to gain enough rep or whatever to mutate the other expeditions obviously a server wide progress bar for each expedition that is visible on the map.
If you need an item from a certain mutated expedition it will take weeks to be able to do that expeditions again. This new system will give us somthing to do to unlock the other ones.
Or they could just mutate them all at the same time and just rotate the actual mutations but this way im talking about will give us somthing to do aswell as unlock what we want.