From a physical interface point of view A LOT has changed. The Solo interfaces with the GoPro via it's HeroPort and the Mini-HDMI connector on it's side.
Solex and SidePilot and Mission Planner all access a video stream which is coming from the Solo thru the GCS' ['Controller's'] WiFi AP. So there are at a minimum [depending on how one views it] two intermediating devices between Solex/SidePilot/Solo App and the camera.
You could spend the $68 a GP4HB is going for on eBay at the moment and still get 4k60 video AND have camera control.
OR, you could put in a little bit of work and install a WiFi-capable Arduino and utilize the script written by a member here to use your GP7.
There are options. But they require, ya know, a bit of work.
Again, a bit of research.