1) Clean cfg, OK this has been done and has returned no benefits whatsoever
"Just" cleaning the FSX.CFG is not enough. I've said quite clearly that the HIGHMEMFIX should be applied so, no wonder you haven't seen any benefit with "just" cleaning the FSX.CFG.
Only apply the Highmemfix.. are you suggesting I do away with all my tweaks which I have spent an eternity getting my sim flying pretty much how I like, to help with CYVR?
Assuming you'll eventually find that with a clean FSX.CFG file + the HIGHMEMFIX the problem will go away, it clearly prove that, regardless of how much time you took to set the tweaks, at least ONE of them shouldn't be used.
After you will isolate it, you might put back all the rest.
Again, ASSUMING the problem is something FSX.CFG. But as I've said, a problem with the FSX.CFG is just ONE of the things to check. It might be a video driver release problem, a video driver tweak or setting too.
It might be a COMBINATION of FSX tweaks and video drivers settings and tweaks. It's entirely possible that a tweak you spent years to find in FSX, could be made invalid by simply updating your video driver.
It's possible that a tweak in the video driver applied ages ago and long forgotten, shouldn't be used with a newer video driver, and a driver clean up might be necessary, removing from the registry everything related to the video card. There a "Driver cleaners" utilities out there for precisely this reason.
3) Use DX 10. Sure, this was the option. unfortunately after having used the recently released DX10 fixer, i reverted back to DX9 due to Vsync problems and other small issues.
If you use DX9, keep in mind you must then be extra careful with memory usage.
So DX10 at the moment is not an option. However, can I ask if FSDT airports will function with the newly to be released P3D V2?
We'll make sure they'll work, of course.