Star Wars fighters (but not the tie) can be added to the mod because they follow the design concept of the fl ships, but SW battleships dont. Adding a StarDestroyer to fl would spoil the FL concept, an it would look weird.
(If you find any mistake in my English, please let me know via a PM)
(Really, I speak terrible English, so please, tell me if I make mistakes. I'd like to improve it a bit )