Details on the three mods.
Unit Pack Link
Adds buildable Brute MK1, Sentry, Sapper, Emergency Turret, Carving Turret, Micro Turret and a more advanced Quantum Relay to the PHC. Adds buildable Saboteur, different version of the Avatar, Serpentine Turret and a more advanced Quantum Archive to the Substrate.
Unit Pack+Engineers Link
Same as Unit Pack, but also lets the PHC factory build the Substrate Constructor and the Substrate Assembly the PHC Engineer.
Prebuilt Extractors Link
When enabled, all metal and radioactive points will have indestructible extractors placed on them.