Here's another link to add to the list. He goes over vector maths and applies it to how to calculate placement for pole vectors. https://vimeo.com/240328348
I am very familiar with Hans Godard's work. After all he has the word "god" in his surname;) I am blown away every time he releases something. The latest with incorporating machine learning within rigging is really something else!
On the note of game rigging, this is something I came across recently. A realtime character face. https://www.youtube.com/watch?v=Vo_FALeUc8c
Is there an added benefit to using the pairBlend node? I see that it has a few extra parameters and it is geared towards translations and rotations whereas the colorblend is "meant" for rendering and texturing.
Take a look at the link below, it might help you a bit?