Are you fighting the NLD-DOM to keep the VA from denying you as well? I see that you have a 20 year AGR retirement locked in. I can do some digging into AR 600-8-4. Your COAs seem to be to appeal the NLD to make them an in service event for the DES. From my experience, just be prepared to be steam-rolled in the DES. If you are unsuccessful in the appeal and the DES does not side in your favor, your next step would be a BCMR. If you are unsuccessful there, then your last recourse would be to bring suit.
Whatever the outcome, I would definitely appeal the LOD. Unfortunately, military attorneys are not that voracious at helping you while you are in. This would lead to attaining a civilian attorney. I do not know what your appetite is to fight this, but a civilian attorney is a huge financial burden. I am at $10k in my case, and I am still in the DES.