In the first picture I am practicing hanumanasana without blocks. The upper body is tilted forward. So the stretch of the hip flexor decreases. Instead, the hamstrings are stretched. The more upright the upper body is, the more the hip flexor is stretched.
The classic form of hanumansana has the upper body resting on the front leg.
There are many variations of hanumansana. You will certainly not get bored.
My first intermediate goal is to bring the front extended leg to the floor.
The leg muscles are tense during the exercise. The energy moves to the center of the body. The legs are not moving away from the body, but toward the center of the body.
I hold the position for one minute, then switch sides. It is definitely helpful to hold the position for two, three and maybe even up to 5 minutes. Yesterday I learned from a man who wanted to learn the splits within 30 days, that he held the stretch 10 minutes.
I prefer repetitions to very long holds.
Holding a position and repetitions are effective methods, which already have general validity.
I just looked up the word 'hamstrings'. I only knew the English word. Hamstrings means back thigh muscles ( rückseitige Oberschenkelmuskulatur) in German. I prefer the word 'hamstrings' in German as well. It’s so much shorter.
Keep practicing, keep learning.
Translated with www.DeepL.com/Translator (free version)