Phas3e's screenshots clearly show that no AA is active in the image at all.
The only AA "effect" comes from scaling down the image in the forum preview.
If your issues are the same, the solution is plain simple and you don't need no Nvidia Inspector (even though there's nothing wrong with Nvidia Inspector, it features so many settings that you'll mess it up for sure, now that you've managed to do so with the standard Nvidia Control Panel already
).
Advice:
Turn off FXAA.
That's all. Turn it off and AA will work.
And while you're at it, turn off MFAA as well.
Background: FXAA is a post-rendering Anti-Aliasing Mechanism. You will see a certain "success" of Anti-Aliasing when you're actually
playing the game with FXAA turned on (but text looks blurred), however since it's a
post-rendering process, anything from the renderer itself will remain aliased, including screenshots.
There is no such thing like FXAA for screenshots.
On Nvidia Maxwell and Pascal cards, FXAA enabled tends to turn off any other AA mechanism for OpenGL games.
FXAA is just a makeshift solution in case your GPU cannot handle "real" AA on your rig/game.
But your card is by far powerful enough to do "normal" AA (aka MSAA) in IL-2, so please use these normal settings only.
Why turn off MFAA? Because that's really heavy on the GPU, it's just a stopgap again and the effect gained is quite small compared to well working MSAA settings.
Turn it off, really.
If you have a few more seconds to spend, I'd recommend to "allow" negative LOD bias and use "High Quality" Textures.
Best regards - Mike