I don't have any experience with Spectrum systems.
I have flown mt FlySky setup for control and 200 mW vTx and a CP antennas, for about 1.5 miles. Alot will depend on how your antennas are installed and the specifics of the location. I had all of the antennas oriented vertically and was flying in a low noise area. I was in the middle of a corn field. No wifi, trees with leaves, metal buildings or hills. All of the above will cut your range.
I didn't intend to get that far out. Where I live, it's an ocean of corn. I got disoriented & didn't know which way home was. I still had video & control and was able to set it down near a back road. I drove around until I found it.
Here is the first of a series of 8 videos that greatly helped me. I recommend watching all of them.
not sure about where your at that you can get authorization to fly BVLOS, but if your going to break VLOS, your going to want an actual long range prototypical like ELRS or cross fire.
I think I have seen people get maybe a mile out of something like what you have there, but that was not with a AR620, but something with an external antenna.
Also at these frequencies, anything between you and your craft (trees, mountains, hills, etc) massively drop your signal. For context, I got a bit of hill between me and my fixed wing once (wasn't paying attention to the terrain) [that or a metal truck and my water filled body at the very least - or all of the above.]... was close enough that if I could have seen my craft to fly it LOS (and it is backpack sized). and almost dropped my control link with ELRS, had I been on spekrum, I am sure it would have dropped.