The current installation (performed by the supplier) of the junction-box (EW-RS910) results in only one port left at the levers for what's usually used for sprint or climbing shifters. This port is found at the left lever (ST-R8050 L).

Can I get Shimano's four-port junction-box (SM-JC41), plug in the aerobar shifters (SW-R9160), and connect one of the remaining two ports of the junction-box with a wire (EW-SD50) to the available port on the left lever and thereby make it work?

Is there a better way, even if it works?