I figured out a fix that seems to work for me. Have only checked this using an external view, but will take a flight later to ensure it works from the cockpit and that it doesn't kill frame rates (Steam, HP Reverb).
Changed a couple of lines in ~\<DCS>\Config\graphics.lua:
Increased Camera --> Extreme --> lodMult from 1.0 to 100.0. Initially changed it to 10 and it got better, 100 was better still.
For good measure, I also made the same change to CameraMirrors --> Extreme --> lodMult.
Increased Terrain --> distancFactor --> Extreme from 1.5 to 2.4 based on an earlier post. This was the first change I made and did not seem to improve matters, but I didn't bother to put it back.
Note that I have my "Visibility Distance" set to Extreme...if you use a different setting, I think you'll need to change the relevant sections in the graphics.lua (e.g. Camera --> <your_distance_setting> --> lodMult.
Good luck, everybody...