A full inventory creates a more interesting problem when leaving something behind changes the next trip. Imagine finding ammo you can't carry: do you use some now to clear a hallway, leave it for later, or drop healing and gamble on reaching storage?
That decision loses a lot if the route back is completely safe. Then the cost is mostly walking time. If an enemy still controls the hallway, carrying a key item instead of another weapon becomes a choice about the route too.
There's a balance, though. If returning always triggers a new fight, collecting supplies could become more expensive than they're worth. A shortcut you earn by exploring seems like a useful middle ground: the risk changes because you learned the map.
How would you handle that balance? I'm especially curious about examples where an inventory decision changed how you moved through an area, rather than just making you take an extra trip. Please tag story spoilers.