So what, you want a bigger slot for the FSD? Say they do let you fit a larger FSD to the Vulture. Then what? You do it and you have to swap for a smaller shield and worse weapons because you just went over your power cap again. The larger FSD will be heavier. Are you going to want larger thrusters to compensate for that? Boop boop boop power plant capacity exceeded. Modules shutting down. Will you come back and make a thread complaining about the power plant output and asking for them to fix that too?
Nyet, ship is fine.
Engineer the FSD. Fit extra fuel tanks and a big scoop then refit for combat at your destination. Suck it up and pay the few hundred KCr transfer fee. If you're so hot in your Vulture you can make it back waxing 2 large pirate ships.
Use your brain man, we have to endure these threads 10 times a day, every day. Don't come in here whining about FD needing to "fix" a problem you already have the tools to fix in game. I'm sorry if I come across as a bit hostile but many people, myself included, have had these problems ourselves. We are more than willing and able to help you, but threads like this are just going to cause 10 pages of arguments and you'll still have a slow Vulture with short legs. Maybe next time try posting a thread in the Ships or Retrofitting subforums about improving Vulture range. There is a tremendous amount of knowledge in this community, and accessing and culturing useful discussions will only make things better for everyone.