I can't imagine doing daily work without multiple Monitors.
In days of olde, you got printed reference guides, which tended to circle my work position. Now they are all 'e' versions. A perfect use for Monitor #3.
Preview on Monitor #4 (an old 4:3 in Portrait. FWIW Most e-ink devices are 4:3.) A perfect use for old hardware . Usually can be had for pennies at Garage sales.
Need more Video ports? Diamond Multimedia make a USB graphics adapter (It will suck up USB speed, so not the best combo if you are a heavy user of external USB disc)
https://www.amazon.com/gp/product/B0...e?ie=UTF8&th=1 I see a USB3 and 4K versions are now available
These work perfect for Edit Sessions ( no rapid screen paints )