We are looking into using a Silabs CP2109 to connect to the BCM20732S. The question is now whether we can still use the WICED-Smart-SDK-1.1.0 IDE (Eclipse) and the associated Tools to program the target device, or whether we can easily modify some configuration settings to achieve this.
As long as the host OS has the drivers for it, the SDK should work with a Silicon Labs part (though we have never tested downloading an app with a SiLabs part). There is nothing in the SDK that is tied to FTDI.
There is nothing to configure. The 732S has a simple UART interface for programming. Much like the FTDI bridge chip on the evaluation boards, the CP2109 only has to enumerate as a COM port on the host computer for the SDK to see/talk to the target.