So, there's been some talk over on the Chastity Forums about PA piercings used for chastity. I'll mention that I have one, and it works pretty well.
This is my second PA. The first one migrated, and I had to remove it. My piercer did the second one a little deeper (poking out further down the shaft on the bottom). She also had to do it a little off-center because I was quite vascular right in the center, and she didn't want to pierce and obvious vein. I bled quite enough as it was.
The "magic sauce" for my piercing (second attempt) was to get it done at a lighter gauge (12 on the second attempt, 10 on the first). I used titanium jewelry, and used sea saltwater for soaks 3 times per day during aftercare. After a few months, it healed up great, and I began stretching it. Now, about 18 months later, I'm at 4 ga, and the piercing is quite durable and well-healed.
Here's a picture from relatively recently after piercing with 10ga jewelry (I think). Note the deeper placement than many, which poke out directly beneath the glans. Also, it's slightly off-center.
Ultimately, I modified the CB3k cage, shortening it. The downside is that the lock no longer lays flush against the cage. I've been using zip-ties, since I self-lock anyway. I'm also still using the old solid A-ring from my CB-2000. The CB3000 rings always bit into me.
This arrangement is quite comfortable.