I posted this on Avsim, but I'll make a note of it here.
I did a fresh clean install of FSX. Loaded only CYVR and a Carenado Aircraft. My VAS was only around 2.0GB. Installed and ran NGX with CYVR and I was up about 2.6-2.8GB. Traffic patterns and all it didnt change much. Added traffic, and orbx PNW with cloud textures and im bumping up to the 4gb limit again. I did the brave thing and went with DX10 and everything is sharper and I gained a couple hundred MB. Took off the HD textures, and Im flying routes in and out of seattle back to Vancouver with no OOM.
Reduced the cloud textures to 1024 which dont look all that bad, and reduced autogen, as well as some non aircraft traffic sliders, and its running ok. Still up there but no OOM.
So it can be done folks. The scary thing is when bigger and better aircraft come along like the T7. We will have to compromise once again.