Does 28-10 slam the back wheel?
I'm running 30/10 and one half-link which slams on my '15 Barcode (13.75). The sprocket is a little worn which helps out. 30/10 w a half link is equal to 28/10 for the most part.
A few years ago I had a S&M made SFA which had a 13.75 slammed rear end. I tried 30/10 and 28/10 but could not get it to work. It was just too tight. I think the fact that the sprocket, cog, and chain were all new had something to do with it. I ended up running it at 14".
The 2015 Barcode is a hair under 13.75. If you sand away the paint in the drop out slots, and make sure your chain alignment is perfect, you should be able to get 13.75 even with a new drive line.