Acquiring technology from a invided star system - it could balance things between players focusing on research but neglecting military (in multiplayer); the problem i can see with AI is that players will invade a system and then let it recapture by AI and repeat this until the AI dont have technology supremacy (you can make a system reinvasion have a 20 turn cooldown to provide technology or something similar) or you can make a rule, that invading a foreign system will grant you a new technology only if the system has improvement, terraforming unknown to invader.

this would break the game by having everyone effectively focus on military tech; massively overpowered fleets can take systems in only a few turns while research can take dozens of turns. in another sense, the tech is an interconnected tree so getting tech that isn't even available to research wouldn't make sense because your empire would lack the per-requisites to even understand it.



If you're talking about improvements, perhaps you can get a one-time research bonus that makes developing it faster if you take a system that has it but you don't, but again this should only be for immediately available tech~