I'm not saying that you shouldn't have a nice base to return to, but that you should try not being able to portal back to that base every night. Go out on a long journey and leave the portal at home. It really is a different game, and it makes you think and plan much more, which is the difficulty that I'm after.

The inventory space taken by portal mats is nothing compared to what you need to pack if venture into mislands and don't know when you might return.

Why would you need a portal to return at the end of a gaming session? Maybe if you're playing coop and trying to coordinate, but I don't see any reason otherwise.

As for the starred opponents, I still don't think that would make any difference. Maybe you could make the previous biome a bit more relevent, but why do you need to go to that biome? Why would you not just avoid it? Doesn't everyone already just gravitate toward black forest or meadows no matter what level they're at?