Due to kids and a suddenly appearing film job my time evaporated, here's where I got to!
2 of the generation ships left earth before it’s final isolation.
Eventually the two clans became distinct and separate, defined by their vast fleet designs, the lofty bats created a fleet of micro gravity ships, they would buzz around, crafting suits and modifying their bodies to fight the atrophy of space. They countered their decaying optical tendons with visual implants and boosting other senses to counter this.
They primarily live in deep space, or the upper atmospheres of gas giants. They use electromagnetic weaponry and rail-guns. Have rituals of caravans and insignia, travelling flotilla.
The Crabs live in spun up stations, primarily hollowed out asteroids, these have been gradually gaining momentum and are now well above Earth rate of gravity, the crabs use huge bulky armour, they believe mankind’s place is to colonise rocky planets and moons..
Hit character limit here :(