One of the kites I struggled and gave up with because of the crowds was a small and rather heavy Conyne which needs quite a stiff wind to get it up, but is quite sensitive to how the bridle is trimmed. It was the one that was in the death loops.
Today i took it to my local field and there was a fitful breeze, with gusts at tree top height. After a lot of careful nursing, I got the kite up to the full length of the string but it was seriously unstable, looping and whirling, and I was having to move backwards and forwards like a caffeinated fencer to keep the tension on the line just right.
So I walked the kite down, trimmed the bridle (2 or 3 attempts) and then nursed it back up. The steeper bridle angle made it harder work in the low wind zone, but once it got up there it was like it was nailed to the sky, pulling but rock steady. I even allowed a passing child to hold the reel - while I had my hand circling the line to catch the reel if he let go. It was pulling strongly enough that the kid couldn't stand stlll.
This is the sort of single line flying I enjoy: spending the time, adjusting and tweaking, and nursing the kite up, fishing for the wind.