In coop's current state, only the host currently gets credit for some things in the game, including a few major season tasks.
Most notably, friends do NOT get credit for the void crusade-related seasonal tasks. The consequences of this are most pronounced with the "Complete 9 Void Crusades" task. If you are playing with just one friend, this means you need to complete 18(!) void crusades for both players to get credit (each person hosting and completing 9). If you have a full party -- 4 players -- you have to complete 36(!!!!!!!!!) void crusades for everyone to get credit. As another example, having to complete the 75 minute perfect void crusade run 2-4 times is simply brutal.
Needless to say, for an otherwise extremely fun coop game, this issue seems like a glaring hole in the experience, and really undermines the enjoyment of friends working to complete the season together -- unless they are willing to devote 2/3/4x more time doing so than a solo player.
Question -- is there any intention in a future update to allow all players in a party to get credit for the void crusade seasonal tasks, not just the host?