For starters you will need more Carafa III if you are brewing a CDA. I generally use 5-6% in my CDAs. 17SRM is more amber in color, think Arrogant Bastard, maybe even a shade lighter. A CDA should be approaching an SRM of at least 30. If you are using dehusked Carafa III or Carafa Special, I don't think it matters when you add them: mash, sparge, cold steep. The roast character is minimal IMHO. I even think a little is appropriate in a CDA. It seems to go well with dank hops like Simcoe, coumbus, apollo, etc. I would not add Sinamar, but that is my own bias because I don't like the taste of it and I can generally tell when it is used. I also, prefer my CDAs without chocolate, but once again, my own bias.