if you're going to fast track, it is going to require getting at least one spot check EVERY day (either during the day, or at night, or both). Can you do that?
I work during the day, so I can't usually get daytime tests except on weekends. To make up for that, I make sure to get at least a before bed test every night. Then I fill in with other spot checks whenever I am able. It helps a lot. Each spot check helps fill in pieces of the puzzle, so we can figure out Shadow's patterns and know what is going on when you can't test.