Perhaps these complicated variations aren’t often taught in yoga classes because they are difficult and not as glamorous or pretty as inversions and arm balances.
Like other deep twists these postures have a detoxifying effect. But Maricy B and D, where the heel of the foot in louts presses into the abdomen, particularly benefit the digestive system, releiving excess gas, indigestion, constipation, and the female reproductive system.
Sage Marichy was not only the son of the God of creation Brahma, but also grandfather to the Sun God Surya of the familiar Sun Salutation. He is credited for discovering this asana of which there are 8 variations. The fist four are included in the Ashtanga primary series.