Some feedback on the Metafalica vs the Replekia and vanilla ships. It's not intended as criticism, but an insight into what I'm thinking while trying to make builds with it that feel good to play:
The Metafalica feels extremely OP-starved. I'm guessing what you were going for was to subtract the cost of its' built-in large weapons from its' usable OP total, but the result is that it's difficult to give it anywhere near the same hullmod loadout as other capital ships, since the cost on capital hullmods is so high. They're balanced around ships with ~360 OP, while the Metafallica weighs in at 250.
Compare to the Onslaught: it also has two powerful built in weapons, and has 360 OP to use, on a ship with 20 lower deploy and supply cost than the Metafalica.
The built in large weapons and the damage type shifting is really cool, but the weapons themselves have so low base damage I wish I could remove them and replace them with Large Energy mounts.
Damage per shot is king against armor. Switching the Metafalica's guns to Type 3 for anti-armor makes them only about as effective against armor as a plasma cannon, but overall much less as they become unable to keep the target's shields flux-capped.
I much prefer using the Replekia as a flagship- I can put large energy weapons in the two front mounts, use the rear large for a medium PD weapon, and it kills targets faster than the Metafalica can, while having more vastly more usable OP for hullmods, as I don't have to kit out the small slots with weapons to shore up damage. (Plus, pretty purple and pink)
In my current game I've gotten the Metafalica before any other Sylpheon capital, so I've been using it a lot more than I normally would.
As a suggestion, I'd do something like this to make the Metafalica more flexible:
Remove built in rear weapon, replace with Large Hybrid slot.
Increase Metafallica's OP by 50.
Increase base damage and flux cost per shot on built-in weapons by 30%.
This would make the Metafallica's guns hit in a similar weight range to the Energy options available, and by refunding the cost of the rear slot plus another 26 OP, the player has a tiny bit more space to work with, can choose to use a different gun or PD in the rear for specialization.