-Yes, the devices are pin-to-pin compatible and they can leave the unused pins unconnected as per the pin configuration in Table 3 of the datasheet.
-The CYUSB2304 provides 4 US 2.0 ports and you could also check HX2VL, our 4-port USB 2.0 hub which is cheaper and has a smaller package.
For more than 4 USB 2.0 ports, please check HX3PD, our USB Type-C PD capable hub, which provides 7 ports but many additional features that may not be needed by the customer.
Thank you for your reply！
I understand very well!