Before you can spawn a S.A.D (Strategic Architecture Droid) or unlock the technology for a Nicoll-Dyson Beam, you need to access the game’s command interface.
To instantly unlock all Giga technologies: research_all_technologies stellaris gigastructural engineering console commands
To spawn a Blokkat Vestige (for farming dark matter): event blokkat_farpoint.1 Before you can spawn a S
Yes, you can drop a Planetary Warform via console: stellaris gigastructural engineering console commands
(Gravitic Anomaly):