Yes, you can divide Fx3 Memory like as mentioned above.
I have modified the bulksourcesink example to the values mentioned above and build the firmware successfully.
And the device enumeration is also fine.
I attached the example project for your reference.
Please let me know the errors/problems that you have faced in your case.
USBBulkSourceSink_Modified.rar 651.8 K
Thank you. If there are no underlying hardware issues with arbitrary RAM allocation, my problems are likely unrelated. I have asked about them in separate discussions.