Suggestions are already here. We commented interesting ideas but this is the most we can do. Johan was clear: "no information". Suggestions are information.
Yes, features related to tech levels are hardcoded. Only solution is reworking corresponding csv files and source code (and this is not a suggestion... this is a fact).
Nevertheless, special tech trees are another story.
In a short resume - impossible to implement?![]()
i don't see how its impossible to change considering moctezuma already managed it years ago with his techeditor iirc