JQC 1.3.4 and documentation
Now with documentation
JSON Quick Constraints 1.3.4 is up with better support when constraining constraining to an object that is not the current armature
It will first look for a perfect match, then with a case insensitive match; then for an object containing the name you were looking for
The documentation is long, and has a lot of pictures and examples. It should be pretty explit
I also made an example file for you to test and learn from