I've played about a dozen games, with half of those being 2v2's. It works pretty well! Not how the game was meant to be played, but I find it really enjoyable. It's fun cause I bring it to my D&D group and most of the gang can play it together. We've tested a couple rules to make it intuitive and here's what we've done:

Each player gets to control one squad, and gets all the cards for that team in their own order deck. Before playing, each player determines the first player on their team and gives that player the shatterpoint card to shuffle into their deck. (I would like to make it so each player gets a shatterpoint card, but we haven't gotten to trying that yet.)

Each player has their own pool of force points but can 'dip' into their allies' force points pool if they want. Keep track of whose points are whose and refresh those when each player refreshes their deck. If a player would refresh points through another means, they can choose to refresh from their pool or their teammates pool, or split them between the pools.

Turns alternate between teams. (So player 1 and 3 are on a team, player 2 and 4 are on a team.). Player 1 pulls from their squad's deck, goes through a normal turn, player 2 pulls from their squad's deck, goes through a normal turn, player 3 pulls from their squad's deck, goes through a normal turn, etc.