So, I've been adding a support ship with a beam magnification array to each of my fleets... trouble is, it has no effect on the beam weapons of those fleets.
I did a bit of digging in the XML and here's what I found.
Beam Magnification Array (BMA) looks to be coded in XML to give a 25% bonus to ships which have a component of type BeamWeapon, but there are in fact quite a few beam weapons of type BeamWeaponEnhanced and those are not specified as targets in the BMA's XML. So, seems like an oversight or, the BMA is designed to boost only non-enhanced beam weapons.
This is also true for kinetic and missile weapons.