Welcome to the forum, first of all.
To answer your question about extending the FPV range of your Vision; yes and no.
the FPV system...transmitter and camera aboard the aircraft, and a video receiver on the ground, coupled with a monitor or FPV goggles, is completely separate and apart from the operating system controlling your quad. It operates on a completely different frequency, with a separate transmitter/receiver system.
by incorporating a separate FPV system into your quad (complete "plug & play" systems are available from a variety of vendors) you can quite easily extend the range of your FPV to many, many miles...in reality, I suspect the FPV ability of the Phantom Vision probably exceeds the ability to control the quad right out of the box ( I should say I don't own a Pantom Vision; I operate two Phantoms with aftermarket FPV systems on board.)
Have you actually flown the quad FPV? I suspect that you may not have, or if you have, the experience was limited. That's not a criticism, more an observation; in reality, at 500 meters you will not be able to see the Phantom from your position on the ground...it's a LONG way away. Something else almost everyone realizes early on in their FPV flying; NOTHING looks like you expect it to from 200 ft. above the ground. When you get 3-400 meters out, you'll be wondering where you are, where your quad is, and how do you get it back to where you can actually see it and know what it's doing.
Use a spotter. They are an enormous help, especially early on. Take it easy, and don't wander too far away. You have a lot of money tied up, and you don't need or want to lose it.
If you're looking for more range after you get your feet wet in flying FPV, take a look at the Fat Shark website for some ideas on those plug & play systems.
