Pancakes and Middle Splits might seem similar but the more you train and practice and the more you improve the more you will understand that they are entirely different stretches.
Both focus on different parts of your body, both are needed for different skills in your journey, yet both are intertwined and depend on each other.
In a pancake stretch your seat bones point towards the floor and the knees point upwards. The main focus here are the hamstrings.
In a middle split the pelvic is rotated. Your seat bones now point towards the back with your knees pointing in the opposite direction. The main focus on this stretch are the adductors.
The pancake is a great and necessary prep exercise for the middle split. By leaning forward we are stretching the hamstrings in an unusual position which prepares them for the middle split.
If we look more specifically at handstand we see that the press to handstand mainly relies on pancake flexibility with only some focus on the middle split at the end. For the straddle handstand on the other side you have to focus on improving your middle split alongside specific strength and coordination.