Note mock differences in README

src/inproxy/README.md

@@ -148,4 +148,8 @@ the module available in `mockModule.ts`. To use this, replace the import in the
 
 The mock simulates inproxy activity and emits events like the real module, but
 without actual users connecting to an InProxy (and without running any native
-code).
+code). The mock does have some different behaviours:
+
+- The data generation process resets on app reload, since the underlying data
+generating process is not being persisted anywhere.
+- The mock module does not invoke any notifications