I don't think they are starting your TDIU claim from scratch unless they don't like the C&P exam results, or want more evidence from your former employer. If you could find out if they are waiting for anything you might be able to supply it yourself. Believe it or not the VA held up my claim because they said they did not have a current DD214 for me. I had been SC'ed for 30 years. Then they said they did not have proof of my last day at work. I got that information them, and I supplied a copy of my DD214. This probably knocked off a year from my claim. What is your current rating percentage?