Now, another interesting question that digs deep into Mac architecture.

I'm able to use both of these adapters on the Mac at the same time:

1. Apple USB-C Digital AV Multiport Adapter
2. Plugable Thunderbolt 3 Dual-HDMI Adapter

When they are working, I get a total of four available independent screens:
- The Mac laptop screen.
- The dual HDMI outputs going to the two 1080p monitors from the Plugable Dual-HDMI adapter.
- The single HDMI output from the Apple USB-C adapter, going to my 720p LCD television near the recording booth.

BUT.... there seems to be a "catch".

If I plug both those adapters into the two ports on the SAME side of the Mac, for example, plugging them both into the two ports the right side of the Mac, then one of the monitors is always blank. Either the TV screen doesn't show up as an available device, or, the right-hand of the two 1080p monitors doesn't show up as an available device. (Depends on which adapter was plugged in first).

If I plug both those adapters into OPPOSITE sides of the Mac (one right side and one left side), then all four monitors work.

Why?

This puts a damper on my idea of having just a couple of cables dangling off the left side of my desk, and no interference cabling coming out the right side of the Mac into my desktop clutter workspace.