I'm thinking out in wwwland must be some general Cypress utility for
transfering minimal data into their chippery to redesignate VID/PID
pipe/endpoints etc.
Put a switch in the SDA line , leave open at power up , so USB designated
Cypress, then after 3 seconds when clock line is high close the switch. Then
upload something to the memory, enough to redisignate the USB identity. Then
power down and power up and transfer the mixer firmware.