Hi Wrongy.
Good questions.
Yes, normally the Root shouldn't be 'deform' the mesh. You should have 1 set of DEF bones that take care of that. This is so your weight groups are nice and tidy, and everything that 'deforms' can be kept in its own collection.
And it would be possible for the base section to follow along with the Root without 'deforming', only if it was a separate object. However, because some verts are moving one way and other verts need to move differently AND it's all part of the same mesh, this would constitute 'deformation'.
So why did I enable the Root to deform in this rig?
Simplicity in learning. I didn't want to add a "base_def" bone, weight the verts to it, and then parent that bone to the Root.
I hope this all makes sense - but let me know if it doesn't.
Thank you for the info, I will copy and paste into my journal and reflect on it. Still trying to understand piece by piece, thank you for the shared pieces. One of these days I will fully grok this.