There's nothing you need to manually keep track of
if you add new bones, you run the script again
I'm sorry, when I said the word "manually", I was referring to the English definition that meant you have to remember to do something, and then do it.
That's just my opinion, I didnt like the approach, so I'm looking for another way. Since ICE is modular by design, there should be an acceptable alternative to what was presented in the Rabbit Rig video.
The point of the video was to answer the question, "What does the 2 Bone IK node do?". I personally didnt know, so I researched it. I think the video successfully answered that question. You can apply the results however you are comfortable with doing, and I think that is the point of community generated content, you can take from it what you want and leave the rest without paying for it first and finding out you already knew 90% of the solution, but had to pay $49.99 for the other 10%.