Based on this spec on the Epson 4900 brochure, I'd assume you can cut BorderFree® images with no margin or paper waste.
BorderFree® Roll-Based Printing
Complete borderless printing on the following roll media sizes: 8", 10", 11", 13", 14", 16", 16.5", 17"
Top and bottom edges can be automatically cut to any length when printing on roll media