What about this...
1. Convert official scripts to the following format:
mes "[Airship Staff]";mes "When you see a broadcast", "announcing that we have", "arrived at your destination,", "please use one of the exits", "located at the north and", "south ends of the Airship.";
2. Save multi-line mes commands into the pot file as a single message separated by newlines.
msgid "When you see a broadcastnannouncing that we havenarrived at your destination,nplease use one of the exitsnlocated at the north andnsouth ends of the Airship."
This preserves the official line-breaks while also giving full control to the translator about how to format the message. Importantly, it also keeps the script syntax clean and easy to read (without newline characters all over the place).