I was in the same boat and since I didn’t hear anything from them in 2 years and my 24 months extension letter was going to end, I’ve decided to apply for naturalization on 08/29. The same day, literally 2 or 3 hours after I started my application, I got a notification saying my I751 was approved, they mailed my new card on 08/31 and got it on 09/02.
I’m not saying the same thing is going to happen to all of us but it’s worth the shot. If we are going to wait for that long, we may as well wait for something better like the naturalization. So if you’re eligible, I would say go ahead and to do it and see what happens. Good luck!