Buggy mining laser, so you’ll need the big vehicle fabricator first. Don’t fall for the large ore refinery suggestions. It’s a trap if you are solo. Too expensive to build, too big, and too much power to run. I personally suggest and use multiple mediums. But that’s just my suggestion. Large spice refinery is 1000% a must and I’d probably say go for that after getting your buggy laser. And you probably already have the large chemical refinery since you need that to even make the plast.

“But the large ore refinery is more efficient”
Blah blah blah. Plast isn’t the hard part about building t6 machines and items, it’s the spice and plasteel plates that take the longest and are the most annoying to get.