Can you use a THIN CLIENT as a standalone PC?

HP t740 - Thin client thin client with pcie slot Expand your capabilities with the HP t620 PLUS, featuring a PCIe expansion slot Virtualization for power users Get high-fidelity, no-hassle connectivity to slot eye of horus Is there anything that can go wrong with using the Realtek ethernet with Proxmox considering that I intend to use the PCIe slot for an NVMe

jackpot party slot PCI-e: The board carries what looks like a PCI or PCI-e slot This is used with a riser card and expansion housing that doubles the width of the thin client