Sorry, missed this over the weekend. I think you'll have a lot less control if you let it age in the barrel, with O2 ingress, more active cultures, etc. Not that it will be a bad beer by any means, but there's a good chance of it being quite a bit different. Either run it through the barrel briefly (with another beer waiting in the wings) and age in the keg or glass, or just give it some dregs in secondary to simulate adding the dregs from the commercial bottle. My 2 cents (or perhaps less).