Not really a modified coupler, they were talks to just modify the springs in the buffering section of the CBC couplers to reduce the jerks at startup. The normal ICF CBC coaches use type E couplers to cut down maintenance and construction costs and have the worst jerks. The AAR type H CBC couplers used in LHB coaches are pretty much the standard couplers in all medium - high speed trains in several countries now. Only a few modifications are expected in traditional coaching stock.