I hope someone can provide a step-by-step guide to match your setup, but I doubt it. There are several guides on this site as you noted. I had the same problem, and my setup is not nearly as nice as yours (I7-7700k, GTX1070) with a Rift S and it took me a LONG time to get something to work without making me want to reach for a barf bag. The problem is that everyone’s rig is SO different and has different programs running and experiences such different results from tweaking that there is no one-size-fits-all solution.
That said, you can do what I did. Drop every setting – and I mean EVERY setting – to low and run it, then slowly increase different settings. I used a spreadsheet to track every change, from the NVIDIA settings to Oculus Tool Tray, to SteamVR, and MSFS itself. Eventually I landed on one that worked, so now I have something I can fall back on while I continue to experiment. And don’t ask for my settings because you can do much better than mine! 
I know that isn’t what you wanted to read, but unless someone else here has a crystal ball, I think that’s probably the best you can do.