Hi Ash,
There's actually an AP report in the RPG.net forums here from when I ran the game
for four players. There's another one from when I ran it
for two players. Both games went very well.
In neither cases did they have separate hunts. It's true that only one Hunter can get on a hunt at one time (with the exception of the qhurym, the ultimate beast). But! You can play plenty of adventures with the game that are not hunts and do not end with confronting a beast. Instead, the adventure has some other goal, such as making peace between two tribes, rescuing a kidnapped tribemember, and so on. The characters can all go on these adventures together in the typical party style.
In multiplayer games, players actually have additional options, such as having their characters assist each other's actions or transferring advantage points from one character to another. Also, the Challenger gets to create more than one threat for conflict resolution that includes multiple Hunters if she so chooses.
So, in short, I've had good experiences running it for several players, even though I initially designed it as a two-player game.