The reason for asking is that I bought a powered USB3 hub recently because my USB2 port lost one of its ports. So I changed it and plugged SBIG cam, ASI 120MM-S (USB3 model) and USB2Serial cable for EQMod in. Surprisingly everything worked but the serial connection didn't. And it wasn't listed with lsusb just as yours. So I think that using a serial2usb connection might not work on USB3. I checked it with both RPI3 and my Laptop but as far as I remember there was no difference.