I wouldn't say that flanking is an absolute prerequisite for it to work. But you do need to move away from where you were listening. And in such a direction that makes both 4th bearinglines(the predicted one from the old location and the real one from the new location) intersect as perpedicular as possible. It depends if you are allready behind the target whether you need to flank to catch up with him and move in front. But you also do not need to get ahead of him to make this work. You could also sprint away in a lagging position to make those 4th bearings intersect clearly. It just means that you'll have to catch up and overtake later for sure. But with a good fix on his course and speed.
I must admit I have only lightly read through your technique in that pdf. And I can't seem to download it right now from filefront to better take a look at it. But what I remember from it was that you essentially make a submerged interception. Adjusting your course until the sound direction doesn't drift any more. Well, it does certainly work if you are ahead of him far enough. Or to say that more accurately, he must have a small AOB to make up for your slow speed. Which you have no way to tell. Also you never know when you are supposed to be on top of him. As you don't what his range is, or what the closure rate is. On top of that, you are draining your batteries. I wouldn't like to go into a fight with my batteries allready partially drained. You'l never know what friends the target has nearby. Personally I find that your way has too many unknowns and guesswork as
a conditio sine qua non.
