Hello
Ten sadly, USB to serial is equal to RS232 serial port in most of it functionality. It supports single serial device connected to it. You will not be able to set different baud rates or other settings.
Over TCP/IP mode means a little different thing. If it is configured as client, it will receive data through serial port and send it to server over yours WAN or LAN connection. IF it is configured as server it will be receiving data through network, and sending it to Serial device over USB to Serial connection. Bidirectional would mean it would act as both, but over IP connection is not happening through USB port.
Best regards,
VidasKac.