assume they didn’t want to emulate an eight-port USB hub on the dongle.
https://github.com/abcminiuser/lufa
Literally a kid did this in high school, this is without hardware support, just GPIO, but he also implemented the full stack on avrusbs and cortex-ms, and one thing he emulated was multiple devices on a hub.
My point is that the PS link doesn't need a dedicated driver, why does this one?