However, the security considerations that affect a USB drive (whether 500GB or 8GB) connected to a router, do not necessarily have to afflict the hard disk drive.
In theorizing a solution, we can ask ourselves if controlling the user privileges of the NIC card access, could actually improve matters for data assurance of hard disk data, (Principle of least privilege.)
We would then investigate if current strategies that address the browser, such as User Interface Privilege Isolation (UIPI) are sufficient, when properly implemented, or if an additional hardware innovation would provide a marked benefit. Some routers (and some Linux implementations,) provide a simple network access “toggle” switch, to limit exposure to network security threats.
UIPI is new to me. Presumably protocols and implementations of UIPI are, (or can be,) standardized, and one cannot suggest improvements without knowing them.