Some thoughts on this subject. Yes, Lardy does the switch side thing on PB. As others have said, just a means of cuing the dog.
But...there are almost always exceptions to most anything.
So, It can depend on the nature of the PB, and depend on the individual dog.
Sorry Wayne, did not watch your video. But, often, under the arc, gives you little room. Depending on the throw.
So, how you approach it may vary.
One dog, you may do very little. Maybe even put your hand down and just send. If that dog is normally not too high, and reliable about casting off a mark.
If you make a big deal with this type dog, often you will get a bad initial line, probably behind the gun. Then you will likely chop up the blind. No good in FTs, mostly. And, that type dog, may be reluctant to go back in, and pick up the mark.
Another dog, you may just do a soft, no bird, dead, re-position a bit, and then send. No switching sides.
And then there are the dogs, you might want to make a big deal about it, on the line. So, that may be a big, NO BIRD, HEEL, switch sides. That dog needs much "stronger" communication. You need to get them in your world, immediately. Or...they will be driving the car, and hot footing it for the PB.. This type dog generally will be quite willing to go back in, and pick up the PB, after the blind (ha)
So obviously, I don't know what Lardy does every day, with every dog. But, my guess, he would say...it depends, too.
Also, it is really not that important, what method you use. Many fine handlers do not switch sides. What is important...Know your dog, know the strengths/weaknesses of that dog...and use effective means to communicate to that dog.
(Sorry to be so long. )