The game already struggles with desynchronization, invisible objects, and bugs even with just two players. Adding a third would likely break world-state syncing.
You can divide labor efficiently (one builder, one hunter, one explorer). It turns the game from a "lonely survival" into a "chaotic group expedition." stranded deep 3 player mod
The (and the more expansive Multiplayer Mod) has become the ultimate way to experience this Pacific survival sim. It turns a lonely, tense struggle into a chaotic group project. Here is everything you need to know about taking your survival party to the next level. The game already struggles with desynchronization