This was too long for comments, oops.

Really great work so far, although I have a few minor comments/thoughts;
- M41 rocket weight is pretty hefty. It feels like a fully geared Marine has a hard time carrying a fully-loaded launcher plus a backup weapon, and it's basically unusable if you're not using the mod's armour. Though I can understand not wanting every marine to be packing an M41 too.
- I don't think you actually fixed the VK's ammo type correctly, but that might be some update ♥♥♥♥♥♥♥ with rimworld/the workshop on my end.
- The costs, balance, and stuff for everything feel a bit weird. All the items seemed to actually be Industrial tier for research purposes, but require large amounts of plasteel and advanced components. Now admittedly the armour *is* very good for this cost, but this also makes fighting the Seperatists a nightmare unless you have big guns with AP ammo, since their raids can occasionally come in with lots of UNSC armour which resists conventional ballistics extremely well. If I hadn't been able to force the raid through a chokepoint and hammer them with Vanilla Expanded Psycasts, they would've overrun my defenses through sheer inability to be harmed by 7.62-slinging militia rifles. I'd keep the Mjolnir where it is, but maaaybe make the Marine stuff a bit less crazy. Or at least have lower partial values for the limbs.
- All the helmets looked like they have 100% jaw protection, even the ones with no actual jaw cover. It might work better if they're made into a modular system with the base helmet and then the eye pieces and mouthguard are seperate? The mouthguard could go onto the same layer used for balaclavas, and eyepieces on the gunlink layer.
- That said it would also be fun for 'fluff' purposes to have armour/helmet variants with stuff like medic/corpsman logos and the like. It'd also be nice to see fatigues for casual use, and stuff like the soft caps Johnson and Stacker had in CE.
- The choice to use custom ammo types in place of existing ones for 40mm and 7.62mm seems a bit weird, but not that big of a deal in the long run.

Wall of words aside, everything's great, and it's nice to have a sort of 'all in one' UNSC mod that's relatively up-to-date. Just needs a little balance polish and then it'll be perfect.