Are you using custom driver for hub?
I am struggling with the same issue - the documentation is crap! it does not say anything about where the command SetPortPower should be sent and what is the code for that command.
Did you ever solve that problem?
The context you mentioned in datasheet are facing to the person who develops host driver, i.e., Intel or Microsoft who provide the driver on PC.
Consequently, if you simply use HUB to make a hardware designm, you don't need to care about these things.
Just follow the hardware design guide to make your schematic and PCB layout.
I wonder if Cypress has considered the fact that Microsoft is not the only developer of drivers. We are also trying to design an OEM system and we need to control the power delivered to each downstream port. The issue is not limited to the HUB itself. our platform is Linux and the OS USB interface is very limited. The OS is not able to consistently map all the USB hub levels that are connected to its root hub, this makes it difficult to use the control interface to send commands to a particular hub. (granted hubs are enumerated in the same order on power up / reset of the OS but once any device is plugged or disconnected the order is no longer consistent). To add insult to injury the documentation of the HUB chips is very tight lipped about how the hubs port power must be controlled. As result we will probably have to go elsewhere for a HUB chip.