Miasma is a vastly underwhelming mechanic with great potential. As the game stands now, there are only a few times when miasma is even a consideration: Ill have to heal after that expedition, Ill have to heal after that tile improvement, My trade route is slightly longer. But ultimately these slight annoyances only occur on one out of twenty hexes and are very easy to mitigate. Ive seen a few discussions about buffing miasma, but I believe that even the current 10 damage can have a significant impact if the map starts with miasma on every hex. Units will be forced to stay near cities, trade routes will be more precious, expansions will be very deliberate, and miasmic repulsers will actually be useful. Most importantly, this will make the planet truly mysterious and alien, and your civs sphere of influence will grow at a much slower pace. It seems odd that the atmosphere is going to start perfectly suited to humanity. We should have to fight for our place. I personally want to combine this with the aggressive wildlife mod to create a truly terrifying experience. I hate mashing Next Turn, and anything I can do to create more tactical gameplay is going to improve my experience. I know I can add miasma with the IGE, but that's one hex at a time. I'd try to mod it myself but I'm on OSX. It's a small adjustment but big thanks if you decide to take care of it.