Okay mo, had a great time last night.
Here's my Carter Hole Thing 3.
Here's how you want to hold it at full draw while using the thumb trigger as the release rather than the pinky. Note the trigger is back in the thumb joint. When applying back tension the rotation of the wrist will trigger the release rather than moving the thumb.
I use it mostly using the pinky trigger. I hold it the same way and notice where the trigger is in relation to my pinky finger, that way I'm triggering it with the tip of my finger but allowing back tension to rotate the release and trigger itself.