I'm in the process of spinning up a Path to Eden campaign. I'm interested in hearing how other GMs have incorporated the Threats to the Ark (Chpt 10 in the core rules).
It is clear that as the GM I can manage it how I wish. For RAW though, let's say I introduce a new threat towards the beginning of each of my ~3 hour sessions. I don't expect any Threat would be fully resolved in a single session. So it seems that after a number of sessions, we would have a number o Threat threads running while the PCs are doing whatever they wish to do whether it is pursue stories on the existing Threats or something of their own initiative.
So I guess what I am really asking is are you, as a campaign GM, just rolling out your Threats a bit at a time and letting them pile up so to speak, or are you doing it more sequentially? Roll out a Threat. Resolve it. Roll out another Threat. Rinse and repeat.