I think you guys need to upgrade to a battlegroup.
Kaz and others each piloting their own smallish ships, going off on their own missions, and acting as a skirmish screen for thunderstrike so giant monsters can't just jump it out of nowhere. These ships would be built small, tough, reliable, but also cost-effective, which means they'd need skilled airship captains to pilot them, rather than just using huge amounts of brute-force magic. They'd be designed to ram and even be lost if need be- with escape pods for the crew in the event of such, assuming they aren't . busy boarding whatever beasty they've collided with.
Another idea was multi-configuration sails- the airships unfurl different kinds of magical sails, at different angles and configurations, based on how they're traveling.
In the sky over faerun, they could have 'wing sails' on either side of the ship, which angle back during combat maneuvers. When they Teleport, they pull the sails up into a 'seaworthy' vertical formation, and then drop hull-first down into a portal. In the elemental chaos, they pull in their normal sails and spars, and unfurl a huge trailing tail, like the tail of a kite, or a chinese dragon, as they twist and burrow through the elemental layers. In the shadowfell and the lands of the dead, the masts are mounted forward, and the whole ship is wreathed in a shrowd of cobweb-like sails which cocoon it and protect against unfriendly incorporeal creatures.