Also, try to find a true USB-C hub. With that I mean a box with one upstream USB-C input and several (>= 3) USB-C downstream ports. As far as I can tell, such products still do not exist. There are many USB-C-docks with USB-C input, various other downstream ports, and sometimes an additional USB-C port which is power-delivery-only, with no data connection.
I have only found one such product at all, but it fits the description just barely: Belkin has a USB-C-hub, but with only 2 USB-C downstream ports, and only supporting 5Gbps and no Alt-DP-Mode on any of the ports.