Rework shields for balance vs armor and better roleplay
Currently: Shield strength scales with the generator size in HS as Size^(3/2). This causes the efficiency of shields per HS relative to armor to increase a lot from one tech level to another, with Epsilon Shields (16k RP) being 40% as efficient as Laminate Composite Armour (20k RP), Theta Shields having 48% relative efficiency, and continuing to increase to a maximum of 75% relative efficiency at high tech levels. In practice, a ship with reasonably thick armor will begin taking internal damage once armor is degraded by about 50%, so a shield which is relatively ~50% as effective as armor is in practice superior against any weapon except mesons, and often is preferable even at lower tech levels against lasers or particle lances which penetrate armor effectively.
On the flip side, small shield generators in the few-HS range are very inefficient to the point of being basically useless. This means that putting shield generators on fighters, FACs, or other smaller ships is usually not practical, despite being a very common fixture in sci-fi settings. While the previous point by itself is okay, since it's fine for newer tech systems to change the combat balance, in my opinion the game mechanics should not limit roleplay in this way.
Suggested change: Rework shields so that regeneration rate scales as Size^(3/2) and generator strength scales linearly with size. This means there is still a tactical advantage to building larger shield generators rather than spamming a lot of small ones, but shield generators of any size will remain viable and shielded fighters or FACs will not be suicide booths like they are now. Shield scaling vs armor will be less extreme as well (i.e. closer to a flat line than a steep sloped curve).
Additionally, to keep shields competitive with armor, the shield strength tech line should be changed to omit the 1.5 and 2.5 values, adding 20 and 25-point values to the end of the tech line. The result would look like this:
Alpha Shields: 1
Beta Shields: 2
Gamma Shields: 3
Delta Shields: 4
Epsilon Shields: 5
Theta Shields: 6
Xi Shields: 8
Omicron Shields: 10
Sigma Shields: 12
Tau Shields: 15
Psi Shields: 20
Omega Shields: 25
For all but the last 3 tech levels the relative efficiency of shields is less than 50% that of armor, so there is an interesting design decision at most tech levels. By the end of the tech line, relative shield efficiency versus armor caps out at 56% which is probably superior to armor but close enough that the choice is not nearly as forced.