Have you considered asking the developer of the Vizio TV integration to make changes to alleviate the need for your Rule all together?
UPDATE: Looks the developer of the following Vizio integration has not been active in the community for over a year. If I were you, I'd simply add a user setting to the driver to allow the selection of a polling interval. Then simply add some code to schedule the refresh() command to run every time that interval expires. You could even get fancy and have two intervals, one for when the TV is ON and another when it is OFF.
