Having followed this exact playbook to validate several products I can confidently say this will give you false positives and the only reliable way to determine when you have PMF is: accidentally get PMF on something so that you know what it feels like (it’s unmistakeable).

Peter Reinhardt from Segment has a must-watch talk for anyone interested in this topic https://youtu.be/_6pl5GG8RQ4?si=pogHC45L58U7K6mW