Hmm, I think I have some more piece of advice to contribute as well!
Aiden wrote. Every time we do a major change it breaks the rig and I have to re mesh the character from scratch. Is there any pipeline we can use that allows updates to the source art without breaking the mesh?
Break down the image in smaller pieces
This makes it sound like your full body rig is a single texture. If this is the case, then the mesh will have to be redone, yes.
If you break your character parts down to smaller pieces, then you'll only have to remove the pieces that aren't needed anymore, without having to redo ALL the work.
Make simpler meshes, with less vertices
Remaking a mesh will feel like a huge task if you're using too many vertices. Try to keep the vertex count as low as possible, it will also speed up the process of rigging. Then, add subdivisions AT THE END and have Spine do the math for you with minimal adjustments.
Blog: Mesh creation tips: vertex placement
Use weights
Weights are more versatile than direct deformations, so I hope you're using them! If you weight a mesh, then have to discard it, the animation work you did through the bones is not wasted and you just have to calibrate the new mesh to the old bones.
Blog: Mesh weight workflows
Try to keep the Spine setup and photoshop art matching
This is so that if a change has to be added to the skeleton, no extra steps are needed to bring it in because you should be able to just import the new pieces and get them under the right bones.
Add new poses in setup animations
For complex alternative poses, this sort of setup can help retain some sanity.
Blog: Rigging new poses - Spine workflow tutorial
