> Tried to display a web demo, some custom diagramming, and a PowerPoint on conference room screen from the laptop. Unable to use the enterprise guest WiFi due to their security proxies, and the hotspot was too slow. Popped the same USB-C HDMI adapter in the iPad, and showed all the content over LTE.

This sounds like more a symptom of wifi's universal awfulness than a failure of the MPB though. I generally use my phone as a wifi hotspot when I'm on my laptop for the same reason.