Cheryl, It's no different than before CS started if you did a private listing from a convo request.
You have to ask the buyer for their zip code or just put a flat shipping cost (if a lightweight item, you don't have to worry since rates under 13-16 oz are the same to everyone in the US.)
You can also do a regular listing and put reserved in the title so it will be calculated by the zip code. (I also use a "custom listing" photo just to make sure no one buys it except the one it's reserved for.
But if you do a custom listing from a convo, it does not have CS and no word from admin when or even if this is a possiblity.