I think we need to define stretching..
There is the often/usual PT way of push thru it no matter how you feel after...
and the gentle stretching mentioned by Sharon Butler.
"just a tiny hint of a sensation"
It is the smallest of a stretch sensation, and if that is too much after- or a day later - then you do even less of it when the discomfort is gone.
You want to aim for no added discomfort from her program, and then move forward slowly & gently to the next step.
I had to read her program quite a few times for it all to sink in about the fascia and how it reacts & is involved. And I have forgotten much but a few parts of it are stuck in my head.