My understanding of the bar infocards on Crete was always that the Corsairs\\\' plans are to steal the technology and capability to build their own biodomes, not to break those glass things of Freeport 9, ship them home, and start growing turnips in them.
The technology used in the Freeport biodomes would be converted in an all out different way, possibly on planet Crete itself.
Freeport 9 is more valuable because its a place where lawfuls and unlawfuls/semilawfuls can trade without persecution. Its important for Crete to get stuff they need from the other houses, important for pirates so they can sell their loot.
But problem is that some pirates care more about their 2 mil they can milk from a trader than for respecting a no fire zone out of RP reasons.