C3e-mb-pcb-v4 File

Where would you actually find a C3E-MB-PCB-V4? Because it is not a standard retail motherboard (like an ASUS or MSI), it appears inside specific industrial chassis:

Even with the V4 improvements, technicians report specific failure modes: c3e-mb-pcb-v4

The C3E-MB-PCB-V4 includes a factory test mode: Where would you actually find a C3E-MB-PCB-V4