I didn't listen to the podcast or read it. I was already familiar with Lewis Lead.
I've tried it before, and it didn't help to amplify atrial activity while minimizing ventricular activity. I believe it simply "works" conceptually because the most common mean QRS vector should be around +30 to +60 degrees and this setup would change the leads to be perpendicular to that making them smaller. If the mean QRS vector is different from that, this won't work. For example, if there is right axis deviation (common in pulmonary patients due to enlarged right ventricular enlargement and also probably one of the more common patients to have atrial rhythms) then this would actually position the leads optimally to view ventricular activity instead. To be honest, once you are very familiar with the different SVTs and how they present, they are kind of easy to spot.
If possible, I encourage you to try it on yourself to see. I was not impressed with my own results. I've yet to try it on an actual patient, but I feel pretty comfortable interpreting a lot of rhythms.