-|SOLVED|-
We have found a solution! The solution discovered is to use constraints inside the 4.17 Animation Graph to copy the ideal scale from one bone to the offending bones.
For example say you have a stretchy spine_01 bone and you want the spine_02 bone to maintain its one to one scale. Apply a constraint to your spine_02 bone and copy the scale of a bone that holds a scale of one.
In an ideal scenario you would export an extra control bone that holds the correct transforms of your spine_02 bone and use that as your constraint.
Here is the result of the Squash and Stretch Rig!
And here is the constraint setup in the animation graph.
In this example I have a constraint node for the spine_02 bone and the head, I have set these nodes to constrain their scale values to the root since the root will always have a scale of one.
Big thank you to Lina Halper for implementing the constraints to make this work, and thank you to @Cyaeou](https://twitter.com/cyaoeu) for helping me figure out how they work.
I’m so excited to have this working and I cant wait to get animating with it!!