YAY!
Now you're getting there; well done
So a de-twang to make it feel more refined now.
And, although your standing supported position may be your favourite, I bet you could tighten that grouping up even further in a sitting, semi-FT stylee position?
The other thing (and I know you're experienced so I don't want to teach you to suck eggs) is, now that the confidence has started to build......TRUST IN YOUR RIFLE. Have positive thoughts. Relax. KNOW that you can do it. Love and caress that rifle and it will repay your trust in bucketloads.. That new found confidence and utter trust will reap rewards.
Again, well done. Good man for not giving up and sticking with it. Let the love affair begin.