I would like to try that .After 18 months I am beging to get a more certain in my  accuracy .by turning my hand parallel to the ground  back Down on release..the thumb loop may just go well with that.
Thanks

Ich kann keinen Vorteil erkennen.

I'll give this thread a bump.  I've been working with the técnica de precisión.  I'm liking it a lot.

https://youtu.be/HSlKTrwbZzM

As long as you dont lose too much control over the pouch orientation it will release well. I can feel this when I rotate and accelerate to the point of release(whether or not I lose control.)what I like about the tight
grip is how secure the projectile is seated, this is safe for bystanders. I never have slippages
. But the tradeoff
Seems to me that it is a little bit more sensitive for release cord fouling the shot.
But either way one learns quickly what works well with the sling and what doesn't. These days I release with the release cord in front of the retention cord (position of the cords in the hand!) whether I use a wide or
tight grip , it just seems to give me the best releases, even on ovals. Somehow
My slings open up with a spiral even though I release in-line in the hand,
The pouch orientates itself for a rifled release.

I often swap between loop on the middle outer and loop on the pinky inner.
Some slings and ammo combos seem to like the former and some the latter.
When I got  slippery projectiles I tend to go for a tighter grip and when I got
rough projectiles I tend to open the sling a little bit by using the wider grip.
Typing on mobile, and I am very tired, so forgive me for any mistakes.