These filters were added so advanced users can influence how JIG works, without:
- Changing core code, so JIG updates don't break the changes.
- JIG getting cluttered by new options that only 1% would use.
However, the power is there in case you need it! The examples are based on real-world needs of beta testers and other customers just like you.
I wrote about how to add snippets to your site. If you are taking it seriously, I recommend the small plugin approach as you can easily toggle it and know what that piece of snippet was for (after looking at it months after). Whereas if you put these into functions.php, that file could get big and chaotic.