Understanding How Pinned Worlds Sort and Behave
The Sorting Rule
Pinned worlds always appear above unpinned ones. Within the pinned group, worlds order themselves by last played date, just like the normal list. The same applies to the unpinned group below. So the full list reads: favorites first (most recent first), then everything else (most recent first).
Why an Older World Can Sit on Top
A world you have not touched in a long time can still appear at the very top if it is the most recently played among your pinned worlds. Pinning overrides the normal position an old world would have had, which is the whole point of the feature.
Multiple Favorites
You can favorite as many worlds as you want. There is no limit and no penalty. If you pin a large number, the top section simply grows, still sorted by recency within itself.
Client-Side Behavior
This mod runs on the client only. Your pins, renames, and ordering are local to your game and do not sync to servers or other players. Nothing about the world's actual save data changes — only how your selection screen presents and protects it.