I think that anyone who owns MSFS has access to the SDK, anyone can develop their own scenery. This guy has begun a no-nonsense, easily followed set of tutorials on Youtube. The idea seems to be similar to the original Windowlight tutorials back in FS2004 days --just show people the steps to make things work, and they can run from there. I learnt a bit watching these, even though I'd already got things started by trial and error:) Lots of error....
https://www.youtube.com/channel/UC0kX_z ... Kvt5YTWGiA