Hub chips often already have pins for per port VBUS control, and you just need to wire P-channel mosfets to them (hub manufacturers often cheap out on this). You can then control port power through sysfs.
In my experience this support was rare. I had an issue a few years ago with multiple USB 3 cameras (Intel Realsense) on a mobile robot that would periodically freeze up and need to be hard-reset, and a power-controllable hub seemed like the least-bad way to hack around it. I found my way to this tool, with its convenient list of compatible hardware:
Of the USB 3 options on the list, several were EOL or impossible to find, and when I ordered one each of the remainder, there was only one I could get working, and it wasn't reliable about being able to reset a device that had frozen to the point where Linux no longer had sysfs entries for it.
We ended up instead using a hub with an internal jumper to disable bus power, and then putting the self power line through a separately-controllable relay.
