For the original release of ES2, whole replacement technologies were used to provide access or exclusion of improvements to specific factions.

Somewhere around the time of Penumbra (?) this changed, and it appears inclusion/exclusion is done via prerequisite within the improvement constructable element, and is automaticaly reflected in the tech tree.

This seems pretty straight forward, and I plan on updating Endless Moons to reflect the new technique to increase mod compatibility.

Is there anything else I should know? Any pitfalls or subtlities I should be concerned with?

So far, things are working. Except for one part.

Most of the time, I can co-opt the descriptors within the technology constructables to make a new improvement appear. But what if none of the tech constructable alternates have a descriptor in common? I tried using an InterpreterPrerequisite OR conditional, but wasn't sure how to modiffy it for technologies.

Also, on that note, is there now a way to make an improvement require a technology without referencing one of those descriptors within the tech? (That might also get around the above problem)