This feels a little bit like a Roman asking if we should build a steam turbine. It wasn’t beyond them to make a primitive version (one even existed!) but the necessary science and technology to do anything useful with it wouldn’t exist for a long time yet. Yes we have an idea of how we might potentially go about it but I don’t think it’ll happen until we’re flinging comets about like pool balls across the solar system.

I suspect if we do develop terraforming tech Earth will be the first target as we seek to undo the harm our mode of living has done to the planet.