There is really no point anymore in buying the B'rel Retrofit if you access to a Tier 5 Shipyard. Fleet modules cost around 4-5 million EC on the exchange and are therefore easily obtainable.
But the main question is why does it get a fourth engineering console? Why not science or tactical? It can't tank anyway and it doesn't need an RCS console with its high innate turnrate.
I would move one of my universal consoles (I think I have a Rule 62 console or Assimilated Module in one of the Sci slots) to the 4th Engineering slot.
Then I'd put it another Flow Capacitor to boost my Tachyon Beam 3 and Aceton Assimilator drains. I could consider putting in a Particle Generator console to boost the Aceton Assimilator radiation damage as well.
The B'rel Retrofit is mostly under cloak, more armor helps it survives as it GTFO's out of danger.
This doesn't really matter. It gets destroyed when shot at thanks to the low hullpoints of BoP's in general, even a fourth armor console won't change that.