I'm not so sure if FF status is that important. As an occasional flyer who can't be bothered with FF programs (such as they are these days) I have had my boarding pass marked TSA pre a few times, most recently on a coach LH flight EWR-FRA. To be honest, it didn't appear to make a big difference in the time it took for screening at EWR. One story I've heard is that the government agency in charge of TSA pre is disappointed in the number of people signing up for the full monty, so they are basically giving out free samples, hoping you will join.