I have been pursuing a special issuance since 2019. I have been flying since high school and licensed since 2004. In 2016, I underwent open heart surgery. On the advice of a CFI, I let my medical expire. Later, when I decided to pursue Basic Med I was told the way to Basic Med for me was via a 3rd Class Medical or SI. I visited an AME in 2019 and submitted all my heart records, and military medical records (100% DAV) which included a visit to the head doctor. I might also add I am diagnosed with Type 2 Diabetes (T2D). As expected, the AME deferred to the FAA. Several months later I received the expected news that the FAA had not been able to establish eligibility to hold an airman medical certification. It included instructions for obtaining additional medical testing for reconsideration: (1) A current psychiatric evaluation, (2) update on OSA, (3) a current neurological exam, (4) a current neuropsychological evaluation, and (3) a current stress test and cardiology evaluation. I complied with all the above. I even forked out $2000 to be seen by an FAA HIMS psychiatrist for the psychiatric evaluation. I was able to see a VA psychologist for the neuropsychological evaluation (which saved me a few bucks). I provided two letters from my primary doctor attesting to the fact my diabetes is well controlled without the use of medication and is considered in remission due to the fact my A1C is 5.2 and my fasting blood sugar is below 100. All testing was normal. My OSA is well controlled via use of CPAP. The FAA HIMS psychiatrist noted, "He did not at any point meet the criteria for a primary anxiety or depressive disorder and the identified symptoms of anxiety or depressive disorder and the identified symptoms of anxiety and depressed mood occurred in reaction to identified life stressors now resolved... He has no disqualifying psychiatric conditions." The VA psychologist noted all testing was normal and, "the veteran does not meet DSM-V diagnostic criteria for any neurocognitive disorder." A later entry in my FAA medical record noted, "Multiple neurologic symptoms. Case discussed at AMCD neuro conference and internal panel. No neurologic issue. Symptoms most consistent with prior psychologic history. No further workup needed in neuro." COVID came on the scene and slowed the process down but I was able to complete the neurological and cardiology testing (all normal) and submit to the FAA. In 2022, the FAA sent me a letter directing me to get an updated medical exam from an AME, which I did in June of 2022. The FAA responded with a request for an updated stress test, cardiology workup, and OSA compliance letter. I submitted all the testing within 60 days. Stress test was normal and the cardiology workup was normal, as well, noting good progress and prognosis. OSA report noted compliance and good daily use of CPAP. Both the AME and myself felt I was on the road to, at the very minimum, a SI which would enable me to go the Basic Med route. In March 2023, I received a denial letter from the FAA. The letter noted the neurological issues and history of untreated PTSD. It also noted cardiac history that has required treatment and diabetes mellitus that requires any hypoglycemic drug for control, and adjustment disorder with mixed anxiety and depressed mood. I was flabbergasted given the fact the FAA medical folks had previously cleared me on the neurological/psychological issues. I was further irritated they were claiming I take medications for diabetes which I do not and I have noted this for them through multiple letters from my doctor. I was surprised to learn I apparently have a history of PTSD since I have never, to my knowledge, been diagnosed with PTSD or otherwise treated for PTSD. I don't know what to think about their response to the cardiac issues since I have submitted numerous stress test, nuclear stress tests, and cardiology workups all noting normal and good prognosis. I really don't know what they hell they want but I do know several pilots with cardiac issues who are flying on SI. So I know it's not out of the question. The letter gave me the option of accepting the denial which would not preclude me from applying again in the future, or appealing to the Federal Air Surgeon. I chose to appeal to the Federal Air Surgeon and fired off a multi-page memo going line by line in the denial letter and including copies of the pertinent FAA medical record and testing submitted. I emphasized the FAA's own previous clearance for the neurological/psychological concerns and wondered why it was being dredged back up at this point. I also wondered, in the letter, if the person reviewing my record had actually reviewed my record and the tests/reports submitted since the denial letter indicated this was unlikely otherwise they would have seen the previous clearance for the neuro/psych non issues, and the fact I do not take medication for T2D, which is well controlled. Anyway, I guess my question is this--is there any point in pursuing this further, especially since testing and workups that clearly indicate good results and prognosis apparently mean nothing to the FAA? I doubt I would appeal to the NTSB as that would get costly but I might be willing, if the Federal Air Surgeon upholds the denial, to immediately see the AME again and start the process over, mostly out of spite but also with the slim hope that maybe a SI will come as a result.