Starsector 0.97a is out! (02/02/24); New blog post: Simulator Enhancements (03/13/24)
Tech-mining should give bonuses to Commerce (increased income)... depending on ruins size.
Tech-mining should give bonuses to ... Ground defenses / Heavy Batteries (increased ground force multiplier), Patrol HQ/Military Base/High Command (increased fleet size) and Battlestations (reduced upkeep) depending on ruins size.