What is the USB architecture in ST60 and LWB5+?

The 8997 has a different USB architecture than the LWB5+.  

The 8997 in USB/USB mode is a composite device – it has multiple interfaces on one device.  

The LWB5+ in USB/USB mode is two separate devices behind an internal hub.  Each of the LWB5+ devices has an interface.  

In Linux, the client drivers are interface drivers, not device drivers.  So in both cases, the driver loads against an interface, it just happens that the interfaces are on the same device for 8997, and different devices for LWB5+

Prior to firmware loading, the 8997 device reports as 1286:2052.  After the firmware is download, the 8997 resets, and reattaches to USB.  At that point, the downloaded firmware is running and it reports as 1286:204e.