Unfortunately, the BCM20730 is not a device supported within the broad market and here on the community website.
Please work with the local/regional Cypress sales team that enabled you on this device to line up the appropriate factory support.
The companies that are selling modules usually don't have design documents. This is why I am asking Cypress as the new owner of Broadcom.
Which companies are building products based on this product?
Please work with the local/regional Cypress sales team as they may be able to help.