Looks like there's finally a #USB4 controller that isn't made by Intel: ASMedia ASM2464PD and ASM2464PDX. I bought a cheap m2 enclosure with them so that I finally have a USB4 device to test my #AsahiLinux driver but figured I'd also take a closer look.
Usually, these PCBs have a Intel Thunderbolt controller, a USB PD controller, a PCIe clock generator, one or two SPI flashes and power/decoupling/passive/etc. components. Looks like these new chips combine most of the active chips since I can only see the ASMedia chip and a single SPI flash on these PCBs.
Unfortunately other USB3-to-PCIe chips from ASMedia also don't have any public datasheets available so I don't have high hopes it will be any different for this one :(