I took only about 15 minutes to set this up and purposely did not use an external monitor because I want a fully portable solution to play low end games (e.g. Fortnite). I know there is a penalty by only using internal monitor. I purposely took the photos in my lap while lying on my recliner to highlight portability.
Lenovo supports ideapad 720s. I wanted to install on a cheaper Yoga 730 as it is 2 in1, touchscreen, cheaper and better value IMHO. Yoga 730 and 720 with i5-8250 can be had between $450-$550 on ebay in mint condition (mine was $508). I bought the graphics dock for $250 including all accessories in new condition.
Worked perfectly and easily with the Yoga 730. I'm sure it would work with my other similar PCs (specter, HP x360, Dell xps 13).
System specs (Lenovo Yoga 730 13.3", i5-8250 8th gen, iGPU - intel uhd graphics 620, Windows 10 home 1803)
Power cord (that came with graphics dock) to power and into dock TB3 cable - one end in graphics dock other to TB3 port (there is one port on my PC that does TB3 and power charging) in order to do pass thru charging and Thunderbolt
Windows does plug and play install of Thunderbolt device and detects a default Windows VGA device
Download and install the graphics dock driver from Lenovo here I only downloaded and installed the driver and not the firmware