In my Mysore practice, the instructors recently added garbha pindasana. It comes after supta kurmasana and is considered one of the core poses to the Ashtanga primary series. I had been doing a modified version for a couple of years when I do my home practice. In the modified version, instead of putting your arms through padmasana, you reach around, bind your hands and just hold your legs. Same with the roll backs. Instead of kukkutasana at the end, you do utpluthi. It is easier but still challenging enough (or so I thought).
As I said, I have done this quite happily for a couple of years but the Mysore instructors will have none of that. It is arms through or nothing at all. Yesterday morning, I was really struggling, thinking to myself, "I've pushed babies out easier than getting my arms through here!" Finally, when one of the instructors looked over at my mess, I asked, "what, exactly, is the benefit of this asana?"
She took another look at me and said, "it is very humbling."
I was excited to stumble across this video which gives an great tip for getting the arms through in a way that doesn't cause flashbacks to the second stage of labour.
Enjoy and may your arms slip through with ease!