I hacked AdobeViewer.app in beta 15.2 so that it reads userStyle1.css in the top directory. I did the same as I did for the 14.2 version. You can get it in the same place:
http://drop.io/pb360ade.
I don't know if there would be any problems using the AdobeViewer.app from 15.2 in the 14.2 version.