Gee that sounds convenient and user friendly.Sure you can do switch test, it's called 'Check Installation', but it doesn't force a guide download when it's done. To force a guide download on a Hopper or Wally you make sure nothing is being recorded and nothing is scheduled for the next 30 minutes or so. You then turn off the Hopper and all connected Joeys and a guide download should start within minutes.
Never understood why there isn't simply a menu selection to force a guide download but then I've only been writing software since 1979 so what do I know.