Hello gwyvern,
Thank you for this amazing mod.
The Update 1.9.6 is broken. The fps decays a lot after a while even on a new game. It is linked to the number of ships in the fleet. With 10 ships, it's not noticeable, with 30 ships.... well the fps drops to 30.
HOWEVER it wont happen if the REFIT GUI is not open atleast once! When the refit gui is open once, the fps drop is permanent in hyperspace until you reload the save, then the fps drop is fixed until you open the refit screen again.
I tested it with the mod activated, it's dependencies & nerelexin + console commands.
IT looks like there is some kind of memory leak or script acting weird based on the number of ships.