Floor L Sit Tuck to One Leg. How-to, proper form and tips

Easier than the L Sit, yet demanding, extend one leg from the tuck position involves the same muscles. See it as an intermediate exercise, while practicing toward the L Sit.
Video demonstration
(excerpt from 'Calisthenics L Sit Progression | Full Tutorial For Beginners'
by Minus The Gym)
How to and step by step instructions:
- Sit on the floor, legs straight and feet together.
- Put your hands on the floor, near the hips.
- Press your shoulders down with your arms straight so that the hips stays of the ground.
- While pressing shoulders down, your head should be as far as possible from the shoulders.
- Raise your knees to the chest so that your feet stay off the ground.
- This Tucked L Sit position is your starting point.
- Extend one leg without touching the ground.
- After a few seconds, bend the knee again, returning to the starting position.
- Now extend the other leg.
Hints & tips:
- Key points are shoulders and abs, ensure they are prepared.
- Other muscles are also involved, this is a complete exercise.
- When starting, to be able to straighten the leg for a minimal duration and bring it back is already a great exercise.
Benefits:
- Overall strength, focus on shoulders and abs.
Counting & gamification:
- Count the seconds you can hold, accumulating in a period (session, day, week).
- Set an accumulated goal for a workout session, say 60secs, and do the necessary repetitions to reach that goal.
Muscles worked and body parts involved:

Muscles: Full body
Primary muscles: Shoulder, Triceps, Abs, Lats, Hip Flexor, Quads
Secondary muscles: Obliques, Lowerback, Hamstring
Floor L Sit Progression

5. Floor L Sit Tuck to One Leg