In short, I'm fairly happy with where I'm. I have made progress, and the breath holding technique seems to work. To be honest, I haven't even checked back on this forum since my last post, because my problem has had so little effect on my life lately. Still using this technique frequently, but probably the due to the extra confidence it gives me, and due to that things are going well in my life in general, I can say that practically I can poop anywhere anytime now without too much trouble.
The only occasion when I truly felt distracted was when my boss came in right after me (I saw him), and sat in a cubicle right next to mine. But other than that, no misfires even if the next cubicle is occupied, I'm at home, and people are around, I can shit in a pub toilet etc.
Pissing seems to be the bigger concern for me now, because it's not so private, so I can't use the breath holding technique easily standing there (I'm a male). I'm concerned that people notice. But still it's somewhat under control, so I don't have major problems. It's just something that I always have to make a conscious effort to manage.