If you're quilting, it doesn't matter. If you're piecing, it really is good advice to not switch machines. Especially if the project is pieced in a complicated manner. But, if you have to, you have to. Just triple check that your 1/4" is exactly the same as your other machine. All my machines have different 1/4" feet and may be a hair or so different from the needle to the edge of the foot. Which adds up over time if I were to bounce between machines.