According to your description, HX3C can meet your requirement. Unfortunately, HX3C reference design is not available for sale. You can contact Cypress local sales if you want to take a look at our demo board.
Matthew Raines wrote:
In addition, I would like to use USB-PD to share power between downstream charging port (eg wall charger), a battery embedded in the upstream device, and a battery packaged with hub IC. The last device will have its charging controlled by either the USB 2.0 embedded device, or a separate controller.
To make sure we're understanding clearly, can you also kindly post a flow/block diagram of this feature you are planning?
Because HX3C is a fixed function part, if this requires a change in the configuration/firmware then HX3C would not be the correct part.