Listen to Kelly. He and a great group of guys are responsible for keeping Solo flying long after the OEM decided to not support any further. It can be daunting/frustrating starting something new but Solo is a great platform for your GoPro and has some pretty great features built into the Soles app, created by Kelly.
I have owned/built a multitude of DJI products from the DIY F450/550 and S900 with their DJI respective controllers and have purchased the P4 and mini. All of them had issues and some no longer function due to lack of support from DJI including abandonment for their custom, closed source apps. I ended up using the Pixhawk controllers on DIYs, the same controller that is used in Solo.
Good luck trying to get help for DJI issues, online and forums are useless for the large part since very limited in what you can do, assuming the apps still works. With Solo and Solex, once you become more familiar with parameters, you can change to fit your specific need and the guys are working on new stuff all the time.
I still prefer my solo, I have four, two in service with fixed and gimbal mount and two as spares. I have recently upgraded to run standard lipo and li ion batteries with new battery adaptors since stock batteries are at the end of their lives. That again goes to show you Solo's versatility and fact it can match new technology as it comes online. You will be amazed and options available for solo including stuff like retractable landing gear and more is coming all the time. So now I can run on li ion batteries which are double the capacity of the standard lipo. DJI doesn't have the new battery technology incorporated yet, but probably will soon.
It may seem like a steep learning curve but there are lots of guys in this forum who will help you. Don't give up yet as you have invested money and time. If you can get over this hump, you will see it was worth it. Solo rocks!