Recently, Thee DocKtor was asked if it was possible to render eight extended HD displays by using two of the award-winning Targus DOCK520 driven by a single host. The client wanted to use a laptop to monitor eight security cameras each rendered on eight different display monitors.
Using a Windows 10 PC with supporting graphics adaptor, this application can be supported by connecting a DOCK520 into another DOCK520 connected to the host PC. It also works when connecting one DOCK520 into one port of the host PC and another DOCK520 into a different port of the host PC (i.e. two separate USB Type-C ports). See the example Windows Display Settings window below.
It was not possible to support this configuration in macOS or Chrome OS, and it was not attempted in Ubuntu. Theoretically, more monitors can be used with more Targus Universal Docking Stations, but Thee DocKtor ran out of display monitors to use in attempting more.