I don’t think kmod-usb3 is in the standard installation. Either it got into the OS with some dependency, or by manual installation.
I uninstalled kmod-usb3 and the upgrade to TOS 7 went without a problem. The USB devices works and seems to work with the correct speed.
Simple benchmark hdparm -Tt to SSD over USB:
Timing cached reads: 1184 MB in 2.00 seconds = 591.88 MB/sec
Timing buffered disk reads: 1060 MB in 3.00 seconds = 352.83 MB/sec
lsusb -t seems OK:
/: Bus 05.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M
/: Bus 04.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 480M
/: Bus 03.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 5000M
|__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 5000M
|__ Port 4: Dev 3, If 0, Class=, Driver=hub/4p, 5000M
/: Bus 02.Port 1: Dev 1, Class=root_hub, Driver=xhci-hcd/1p, 480M
|__ Port 1: Dev 2, If 0, Class=, Driver=hub/4p, 480M
|__ Port 2: Dev 3, If 0, Class=, Driver=pl2303, 12M
|__ Port 4: Dev 4, If 0, Class=, Driver=hub/4p, 480M
|__ Port 2: Dev 5, If 0, Class=, Driver=cp210x, 12M
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=orion-ehci/1p, 480M