Everything you've listed has nothing to do with quality control, but rather with development and extensive long-term testing with problem resolution, an extremely high cost factor for the manufacturer, which is usually cut these days.
Quality control only takes effect during/after production.
In these cases, these clicking noises are a grounding problem with all connected devices and very rarely with a single device.
I know that most users don't want to hear this because it's much easier to blame a single device, preferably the last one connected.
One indication of a grounding problem is that the clicking only occurs via USB.
However, grounding problems are incredibly complex, very difficult to locate, and sometimes very difficult to prove.
The amplification factors of the individual devices also play a role. Often the clicking or other noises are so quiet that the grounding problem goes unnoticed.
For me, these DACs don't cause any problems at any of my three desktops, all Macs, occasionally an HP notebook.