Thanks very much for that information, Shonky.

I had indeed seen that Targus unit at the DisplayLink web site (they link to it on this page), and I will probably upgrade to it, or something like it with the new 4k/60hz chipset at least, if I get new displays.

Do any of these USB3 docks support charging a Macbook plugged into it? Or am I destined for a second power cable as long as I'm tied down to DisplayLink?