Upkeep doesn't really matter to the "big alliances." They have sufficient moon goo income to not really care.
Maybe create a vulnerability for Super-Capitals that makes Frigates down right terrifying to them.
Classic Star Wars Ep 4 - Death Star Trench Run style vulnerability. I don't know what that would be, but it would make hotdropping a gate without support a horrible idea. "PL is hotdropping 20 titans on this gate! Quick tell anyone with an Inty, time to open them up!"
Perhaps another option is to break down the ship into target-able subsystems (maybe for all Capitals). The opportunity to make the ships "dead-in-the-water" could be interesting.
Just spit balling.