You don't. It is not required to visually ensure anything. Do you visually ensure your flaps are out on every takeoff? No.
Yes you check the reversers during your walk around. But a walk around is classified as pre-flight. It has nothing to do with the actual operation of the aircraft once moving under power. So no, unless you can quote the article, I'd say there is no general rule or law prohibiting the use of reversers during taxi other than the usual type-dependent operational guidelines which may or may not prohibit their use.