Hi Steve,
As I mentioned before, I run my three 22 inch monitors at 5295 X 1050 in nVidia surround using a RTX 2080 and the same CPU and main memory as you. It runs pretty well in MSFS. When in surround, I try to keep my FPs in the low to mid 20s by controlling FPS. I use mostly high settings (one step below Ultra) and it looks great. If I don't control FPS the system will run at 30 - 35 FPS or more, if it can, but there is more stress on the 2080 demonstrated by temeratures approaching 85C (it throttles at 89). I am comfortable with 20 - 25 FPS so I try to keep the FPS at that level and save the strain on the RTX 2080.
Since MSFS is really not yet optimized for multi screen, there is some zoom distortion on the left and right screens though I stay zoomed a bit to minimize that. MSFS seems to run at about .50 zoom factor when compared to FSX/P3D's zoom scale. Also, the enlarged lights at night (halo.bmp) issue exists, when in Surround, and can't be adjusted, as far as I know, via a halo.bmp mod like in FSX. This is also due to the lack of full multi-monitor support. It is important to note that full multi-monitor support is on MSFS's list of fixes in progress.
MSFS is my second sim along with P3Dv5. I also have P3Dv3 and v4 but don't really use them. The visuals in MSFS just keep me coming back.....the view is so realistic in the majority of scenes.
Rid