Can these railings be joined or once the 6 Ft railing is cut in 4 Ft piece, the rest 2 ft is wasted?

Hello, and thank you for considering Trex railing. We unfortunately do not have rail extenders, so once the section is cut it needs to be discarded unless you have a 2 ft section between posts where it could be used. Kindly, Elisabeth-Trex Customer Care