Yeah the NDU fix did turn out to not fix it for me, I had gotten lucky after applying it and the bug happened to not trigger after a very long BF4 session, so I was pretty sure I had fixed it because I had typically run into it after around an hour or so. A few days later it happened to me again (I alt tabbed out of a game and noticed 8 gigs of ram in non-paged pool memory usage so I was able to reboot before it used all my ram that time). One thing I noticed is the leak seemed to happen pretty quickly, starting at the end of the match. I had alt tabbed out during the match, towards the end and the mem usage was normal. alt tabbed out again at the very end, and 8 gigs were in non-paged pool all the sudden, so it doesn't seem like a very "slow" leak. All the times it happened previous to that I noticed the lag started near the beginning of a new map, so I suspect the leak triggers around the end of a map, and the symptons can begin on the next map once it fiils your memory. It doesn't appear to be map specific, at least not that I can tell.
So far after applying the win7 compatibility fix (and in addition I'm using the 32-bit exe) I haven't triggered it again after another long session and a few subsequent shorter ones, but its very hard to tell with this bug since its so random, and a few others have said this hasn't worked for them (such as the post right above mine!). I'll try playing more today.
This bug is tricky because you can't really reproduce it "on demand", it just kind of happens randomly ☹️