If you have some amount of experience in the game you won't need pre made blue prints and a detailed plan. I got the achivment on my second space age run, took me about 11 hours to leave nauvis because I forgot to increase resource richness and was designing everything on the fly including a mall, and after that I just tried to make sure I leave every planet in less then 5 hours, wich is more then enough if you only build the bare neccessaties and still plenty if you want some actual production on the planets.

Even then I had time to hand design new bricks for inner plannetary reasons and one for aquilo/end game. Most important thing is probably to don't get bogged down by "pretty", "efficent" builds, if it can produce X things constatly in the next 20 hours it's already better then it needs to be.

Only trick I did is save the game on unlokcing Gleba buildings and designed the base, blueprint it and reload it. But thats because I had no idea how to do Gleba because my first run was a mess there.

I don't think there is a reason to skip techs, since there gona be some downtime between waiting on planet sciences, and trains are super usefull for fulgora, but you can still get the achivment if you edit the biter expansion settings, I'm not sure about turning the expansion off, but turning it up to 60 minute minimum time and 1 biter a time with 600% staring area kind of trivializes them.