The hub with built-in HDMI is simply a USB hub, plus a USB-to-HDMI adapter, plugged into said hub, all inside a uniform enclosure.
So if the "built-in" one works, then so should the external USB-to-HDMI adapter.
It's all DisplayLink stuff.
Or maybe not. Those hubs are so cheap, I'm wondering if perhaps they actually use the "DisplayPort" signalling rather than licensing a DisplayLink chip. If they really do use DisplayPort, that would explain the low prices, and the performance should be excellent as it would be using the notebook's GPU.
http://www.laptopmag.com/articles/usb-type-c-faqThe part I am still not clear on, is whether DisplayPort can run simultaneously with USB on a single port.EDIT: Ah, yes.. dedicated pins (kind of):
http://www.vesa.org/news/vesa-brings-displayport-to-new-usb-type-c-connector/So, yeah, that hub is probably using DisplayPort to export the native notebook GPU's output to its HDMI connector.