Dual Ethernet Carrier Board - VL805

There is a chip on the dual ethernet board that takes the PCIe and converts it to 4 USB 3.0 ports from Vialabs called the VL805-Q6. The chip has its own firmware which sits on a dedicated NAND flash chip.

This VL805 chip is also on the raspberry pi 4, but on there the controller firmware only activates 2 of the 4 USB 3.0 ports. But on this Seeed board at least 3 must be enabled to allow for 1 to run the LAN7800 gigabit ethernet chip. Does Seeed have their own custom firmware that they put on there? Is it possible to change it? And can it be changed from the raspberry pi through the PCIe or does it have to be done directly on the NAND Flash SPI lines?

I’m curious because I want to play around with which ports are enabled and if it affects speed.