To add, it would let faction mods differentiate themselves more. Oddly enough, I recently had the idea of another shield-type that always has 360-degree coverage, but takes longer to raise. During the raising, it progressively blocks more damage, otherwise letting some percentage through. (So at 25% effectiveness, it blocks 25% of incoming damage while letting 75% through; might apply to Flux efficiency as well.) This is for shield-centric factions, encouraging leaving your shields up and never dropping them unless you are well away from combat. (Armor and/or hull would be paper-thin as appropriate.)
So as a gameplay mechanic it might be questionable, but as a game-engine feature, it'd be useful.