I am looking for the best way to build a nice 22x Arti MC Oceanic that produces a lot but also is well defended.

As of now, I have a VM icy that is 5x MR and producing 392.7 aph. I am talth so in about 20 days it will be 15x, after which I will use 5 enums to make it 20x then a melter to make it 22x and MC.

I have yet to max out the passives (only 600 passive cloak and 1300 passive defense), but here are the stats (after legion bonus):
1470 Population
33510 Defense
3030 Attack
5333 Cloak

Structures:

• Astrobiology Ward Population: 500, B Population: 50%
• Resonance Inhibitor Cloak: 250, Invasion Defense: 500 (x2)
• Adumbrate Station Research: 1, Artifact: 1, Cloak: 200 (x2)
• Archaic Stasis Cells Population: 200, Invasion Defense: 500
• Dark Anti-Beacon Defense: 500, Cloak: 150
• Domain Walker Attack: 600, Defense: 600 (x2)
• Ergosphere Filter Cloak: 150, Cloak: 20%
• Galactic Concord Station II Mining: 2, Artifact: 2, Defense: 20%
• Obviation Barrier Defense: 1200 (x5)
• Barrier Nexus Artifact: 1, Defense: 300, Defense: 20% (x2)
• Isolation Bureau Mining: 2, Research: 2, Artifact: 2, Cloak: 400
• Hyperforge Fabricator Artifact: 12 (x2)
• Scruuge Lab Mining: 1, Research: 2, Artifact: 1, Attack: 300
• Processing Core Mining: 1, Artifact: 1
• Trellith Comm Relay Research: 2, Artifact: 2
• HyperSensor Satellite Research: 2, Artifact: 2
• Hypergate Mining: 2, Research: 2, Artifact: 2
• Space Elevator Artifact: 1, Population: 50 (x2)

What can I change and what should I add once it is MC (this adds 12 more space)? Thanks!

The Auric Lepus Drone 3.0 drops. Two of them.

Replace 1 space elevator with Lepus Chromatic Gateway, +30% pop is worth more than 50 pop.

Replace Ob barrier with Klorvis Gateway and Crimson Rift Aperture

Replace Ob barrier with warp inhibitor

If possible, upgrade Dark Anti-Beacon to Dark Null Beacon.

Remove 1 Hyperforge (+12)
Replace with:
2x Zolazin Analyzer Research: 1, Artifact: 1
1x Scruuge Hovertank Artifact: 1, Attack: 15%, Defense: 15%
1x Captured T.O. Harvester III Mining: 2, Artifact: 1, Population: 600
1x Orbital Stabilizer Artifact: 1, Bonus Mining: 7%
1x Processing Core
1x Silthion T-Plasma Vesicle Research: 3, Artifact: 1, Cloak: 300
1x Antimatter Drill Mining: 1, Artifact: 1, 400 attack
2x Quantum Accelerator Artifact: 2, Cloak: 150

Size 12, +12 artifacts... And room for more stuff.