If my memory isn't failing me, there's an OmniFighter configuration that also has an infantry bay. I think these configurations are used to quickly deliver a squad of battle armor in an area and then sticks around to provide Close Air Support for the squad. For example, a squad of battle armor is dropped off next to an attacking pirate force and spots for ASF attacks. Or, as you suggested, the Troika quickly intercepts a pirate JumpShip and deploys battle armor marines for a boarding action, then engages any other pirate aerospace assets.
And yes, basically this means you can bomb the enemy with battle armor. ;)
Edit: Similarly there's the Seleucus DropShip from TRO:3145 Free Worlds League with an eighty (80) ton battle armor bay. It basically does the same thing as the Troika-6T, but with an entire company of battle armor.