Personally, my view is: wait until you're symptom-free (or have negligible symptoms) before experimenting with the booze. Alcohol might have some benefits for healthy people, but I think if you're recovering from PCS, better to err on the side of caution. My occupational therapist (who has worked with various people with brain injuries) concurs.

Your brain is in healing mode, and it isn't clear that the "one drink can be part of a healthy diet" dictum applies to people with PCS. If I'm not mistaken, doctors usually suggest that even healthy people who don't drink probably shouldn't start, even if very moderate amounts of alcohol may confer some benefits.

Plus, we now know that PCS can cause or contribute to depression, and alcohol is a depressant. I would stick to the basics: rest, good nutrition, appropriate supplements, activity/exercise that doesn't trigger symptoms. Give your brain the best chance of healing. We still don't fully understand what is happening in the brain during the recovery process. I would mess with this process as little as possible.