Agree. Although, completely is a broad term. Someone will always have an excuse not to.

But we def need to ensure we have a 100% clear idea of no ecology. Plus a clear mapping and review of all geology.

But honestly. Before actual terraforming. We need the tech to build an artificial magnetic field. Anything else, honesty can only be generating atmosphere within enclosed environments. As plant and human life will not be successful in open air. And any atmosphere will need constant replacement.

This moss can apparently survive for a short time. So would be a huge help. As minor breaches will leave the moss able to produce oxygen. Def bloody useful in any form of colonisation.

And let's face it. Any true study of the planet. Will need people. Even if most is robotic, the distance from earth is such that having experts on the planet will make a huge difference. 6 to 44 mins for a round flight communication. While doable as we see. Cutting it to near 0 will really be essential for a full investigation. Even with way better AI then we have now.