4-player split screen unplayable with lag

Me and my 3 kids tried playing the beta with 4-player split screen. The game crashed a couple times and we died several times due to lag. We struggled to open chests, go to sleep, or open a workbench. Elytra's would also disengage randomly during flight. I reduced the maximum FPS to 50 and dropped the render distance to 12 chunks but it did not help. Our FPS was consistently in between 6-12 but seemed to cap at 35. Our world is an average strictly survival world without massive builds, red-stone farms, or a large amounts of entities that would cause the game to struggle. The only thing that helped was if one of the players signed off. As of now, the beta functionally caps out at 3-player split screen.