I agree that this is a valid concern, and that there will be challenges in picking a course… that’s why I’m mentioning it now.
I’m personally in favor of lifeshaping-biotech as a non-psionic non-magic ruleset… it brings a lot of interesting options and potential to not only Athas, but also for other settings and DMs that might want to have genetic horrors or better grafting rules or alterations be a thing in their games. Ancient Avangion? My brainstorming imagination promptly throws up (time travel of a future avangion, or a temporal projection of one into the past, the Spirit of Athas itself manifesting to prepare the Thri-Kreen - the real chosen of Athas - for the things to come so that they would survive, a manifestation of an ancestral spirit that wasn’t an actual avangion but was something else… maybe the avangions modeled themselves after it instead! )
How much are we trying to create a toolset for the DMs and Players with the Lore, and how much are we trying to stick to/grow from the existing Lore… and if there is going to be a break and change, when and where and what direction should it go?
I actually have my own ideas, but they are somewhat skeletal and more based on making it possible to bring in specific mechanics than anything else. ^^
I would also favor a democracy-styled approach to deciding, rigged just enough to prevent deadlocks, but also acknowledge the advantages of having a benevolent monarch in providing a clear direction.