Please refer to the following links:
2.) You can also refer to section 9 of AN75779
3.) How to connect two image sensors to FX3 and stream UVC - has an example project attached for 3 UVC cameras attached in the interactions.
The above threads discuss about the ways in which multiple cameras can be used to interface with FX3/CX3. Please go through them and see if your application can be implemented as described.