I'd like to suggest the addition of some reward boosting models to encourage people to log in frequently.
Quick Match:
Players will queue for a random map once a day, including paid campaign maps, for increased rewards. This will include F2Pers, however they will not unlock Alien Myths specific content where necessary (such as Shae in In Shock, or certain blueprints). This will widen the map pool and shorten matchmaking times for people queuing for specific maps. An example of this would be Duty Roulette in Final Fantasy XIV. After the match is concluded, a reward is given to the player for completing the daily, separate from any in-match rewards, but it is not repeatable. This would greatly improve player retention, and it would also allow F2Pers to demo the other maps - which would encourage them to buy the campaign.
First Win of the Day:
Grant players a bonus reward for their first win of the day. This bonus could be a flat reward assigned post-match. E.g. 5000 G
Single Player Mode:
There's an option to play offline currently, but there's no reason to do so. Playing offline should offer a small gold amount at least based on difficulty. There are times when people don't want to play against an antagonist, or with other people, or they have network outages. Allow these players to play the single player mode for the reward they would have received playing the map for the first time. It's a decent way to reliably farm gold if you really don't feel like playing online, or can't. Either way, incentivising this mode adds options to players, and also stops this mode from being entirely irrelevant. The Gold rewards offered in single player aren't high enough to draw people away from multiplayer permanently either, but it still functions as a means of slow, stable progression.
Antagonists Exclusively On Prologue:
This is more of a remedy to an existing problem. I'd suggest removing the confirmation pop-up describing the map when queuing as antagonist. There's a real problem with Antagonists spam cancelling anything that isn't the prologue mission, so concealing which map they're entering would help things slightly. That said, most maps are heavily skewed toward raiders, so you'd be getting a lot more antagonist disconnects. I'd recommend reducing the respawn timer on antagonists to compensate on these maps. I'm just tired of rarely getting antagonists on anything that isn't Prologue.
Update: This change has been implemented, here's hoping it solves the issue.
Antagonist Mode Quick Match:
An added solution to this would be, again, to offer a quick match mode for antagonists, where once a day they will blindly enter a map and receive 2 added stigmas once the game is concluded. One of the biggest complaints about antagonist mode is the lack of reward on a loss. Having a small daily reward of stigmas regardless of how the game went, would encourage more people to play the mode, and be less likely to quit midway, or drop if they get a map they don't think they can win. This won't really affect the hardcore antagonist players, but it will get more casual people to get into the mode, and possibly get them to come back for the daily bonus.