Yes, did one for our tack release line (which we no longer use) and on a strop for a flying block for reaching.
We were discussing them tonight as a boat in our fleet uses them for jib sheets. I'm not convinced as I'd prefer the option to replace the soft shackle if the know starts to slide (ours do sometimes if not cinched tight enough when made).
I spent some time working on a similar idea and have it posted on my site. But my conclusion was that these integrated soft shackles produce odd forces and there is a loss of strength at much effort. Much more straight forward to do a standard tight eye splice that captures a conventional soft shackle. I have been using this on my main halyard for years but am going to replace that with this https://l-36.com/halyard_shackle.php
In some instances integrated soft shackles are contemplated to avoid losing the soft shackle when it is opened.
Instead, any soft shackle with twin legs can be made captive, but the eye it is attached to needs to be formed subsequently (or if the eye is already fixed the soft shackle needs to be constructed around it).
Below are a couple of examples in use on our boat.
The first is the soft shackle the attaches our snubber to our chain. It is very useful not to have to fuss with closing it as soon as it is released. The eye of the line was spliced around an existing soft shackle.A few went overboard before I adopted this practice .
The second is where a soft shackle is used in a low load application and needs to be frequently tied and untied (it is used to help secure our dinghy under the solar arch when on passage). Rather than splice an eye in the line, I simply tied a bowline around the soft shackle, as the extra strength was not needed.
I use versions of that all over, being a former foredeck guy for a gent that used 3lb stainless shackles , I want to get hit in the noggin with a soft shackle. They dont rip stuff , they dont clang and dont snag as much stuff. I'm a huge fan
I have used the premire ropes integrated soft shackle before and have gone back to just a tight eye splice and a soft shackle set up. The problem is that the shackle will start to wear out before the rest of the line. You can just swap the shackle anytime with a tight eye splice. And maybe you want a different configuration for the shackle in the future.