Well, I did as I said. Reinstalled it over unchecked read only, after I validated my game files to reset to 1.02.
I found no difference in performance or visual effect. Once I was done reinstalling, the files were again checked to read only. I then recorded (using Fraps and EVGA precision ) both flights with checked and unchecked read only files, with an exact result in both performance and visual. FPS 34: AVG. 48: Max. 60. Precision recorded no more or less usage on the GPU.
Myth......busted
Valiant effort though OP. Keep looking.
CHEERS!
Whiskey