No iGPU (but dGPU) & main monitor?

[AlbanRampon]

Hello,

These monitors would indeed be suitable for what you wish to achieve.
Having a dGPU and no iGPU doesn't make a difference, except decreasing complexity.

DisplayLink solution is not an external GPU so Windows 10 will send the CAD software computing tasks to your dGPU like it would with a directly connected display.
The benefit of a software encode is that, like you state, only 2 USB 3.0 ports are necessary. We starting doing 1080p over USB 2.0, so USB 3.0 bandwidth is more than comfortable.

If your workstation is a laptop, you have to keep in mind you will be powering 3 display backlights from one battery. That, and a computing intensive CAD application, are bound to reduce your autonomy.

Kind regards,
Alban