Deep static stretching helps manipulate the fascia, tendons, ligaments and muscles for very focused mobility assisted by the breath.
It’s so important to breathe deeply with intention when practicing asana held for long periods of time to ease the discomfort, mover further into the pose and find more space.
Yin yoga is a slow pace which can leave time for your mind to wonder, try to concentrate on yourself, on your body on your mat. Notice what you are feeling physically and mentally. Yin is very taxing mentally. Working through discomfort, with the aim of relaxing through the difficulties is great practice for everyday life.