Yes, I have connected my focuser (ASI EAF/Pegasus FocusCube), Guidingcam (ASI290mini) dirctly at the Raspi, and via an unpowered USB hub an SSD and the mount (EQ6R). Focuser and guiding cam are connected via the two USB2 ports, the QHY to one of the USB3 and the hub on the other USB3 port.
I use this setup for almost a year with no problems.
P.S.: for completeness: The focuser have to be connected to 12V seperatly, also of course the EQ6R.