My take on the new CS/FAR 23 "consensus standard" approach is that for the time being you're stuck with a lot of negotiation with your authority to get anything through as there isn't yet published list of accepted means of compliance with it, and quite probably they won't allow cherry picking on existing aeroplanes. I should stick with the standard on the TCDS, or issue 4, rather than getting caught in a negotiating spiral with your authority.
G