I've used Ace skeleton stocks, you won't get much better of a cheek weld if you're already running an M4 or even a standard A2 style stock. The only thing the Ace will give you is a little foam padding, the streamline and angle of the upper portion of the stock is the due to the buffer tube and it's assembly. IF you take off the foam pad (tube) you may get closer, I would look into a different mount. Or even use higher rings, I'm not seeing how swapping out your optic will help either, your going to have a similar eye relief unless you go higher with the mount.
Sometimes on AR platforms you just have to do it.