Question Full Body Awareness Ik and Animation problem

So before I posit my problem, I need to lay out my objective and that is to create a full body awareness fps controller. I have animations divided up into two different layers, the lower body (hip and legs) and the upper body. I do have an IK system set up for the spine and aim. So what then is the problem? Well due to some nature of how unity handle things that I don't know about I've run into a situation in which I cannot create results that I particularly like.

The way that I have masked my animations was using the transform selection in the avatar mask creator (because I'm using a generic rig), which in itself is perfectly fine. However if I do not mask the root joint in with the upper layer mask, I get results like this:

https://i.imgur.com/JwpngJ3.mp4

The legs are animating exactly the way I want to, but the spine functionality is borked and in the FPS view everything is unstable.

The second one has the root included in the upper mask:

https://i.imgur.com/7zDEK5B.mp4

The IK spine is perfect, the FPS view is perfectly stable and responsive however the legs are floating in space and do not rotate to the correct positions when the character strafes left or right.

How would I go about and achieve the best of both worlds here in this situation? I'm primarily an artist but would hiring a programmer who specializes in this be useful or are there additional tools that I don't know about that could help me with this? Thanks!