I got off 4546B but not without doing some housekeeping first, like letting all the creatures out of the AC and Aquarium.
I put some supplies on my ship and that's about it.
I did manage to 100% the 17 achievements, that surprised me.

I put a Cuddlefish egg I found in my Time Capsule, along with some Kyanite . The Cuddlefish I had around my main base, it disappeared near the end, I hope it's okay.

Not meaning to be melodramatic but now I am experiencing what other players mean when they say they wish they could experience Subnautica again for the first time. There were so many awesome early experiences in this game, like finding the jellyshroom caves, finding blue prints, using the Sea Glider & Seamoth, building your first habitat, the terror of finding the leviathans, or rather, them finding you. Figuring out where you can traverse safely and what places to avoid.

One of my best mid-game moments was creating my first Scanner room. I didn't know what to expect, but that was cool. I wanted to build scanners everywhere, to see as much as I could. I didn't care about speed but I upgraded all of them to 500m.

I built a base with a long glass tunnel to an observatory stretching into the ecological dead zone behind the Aurora. I hatched a Gaseopod and let it ago near this base and they seem to get along with Reapers. I had very interesting moments observing the Reapers close up, swimming around my base.

Another base was by the medical facility and I hooked that up to an underground geyser for power.

Something I started exploring was building outdoor grow beds and filling them with brain coral. I wonder if you could build enough so you could swim through the lost river, just going from grow bed to grow bed. Probably best to try this experiment with the jellyshroom caves first.

PRAWN Suit was fun, but Cyclops was incredible. I did a storage load, checked all the watertight hatches and did some sea trials. Generally kept power at Ahead Slow and I never had any power issues, even though I did add two Ion Battery cells later. Ahead Flank just makes it catch on fire. My most stressful parts of the play through were taking the Cyclops down the Lost River before I was ready - it maneuvers like a moving van and taking the PRAWN Suit deep and not having the suit jump upgrade. Getting back to safety was questionable for a bit.

I never did find the PRAWN Suit grappling hook blueprints.

Great experience, great game. It's funny how the places in the game seem so real. I can picture the layout of my primary base, all the storage, tools and other interesting touches I added like desks and benches and posters as well I can picture my own house.