Long story short, im using the cc4 base model. I have exported the model to zbrush, made changes and re-imported it back into cc4 and made a morph slider out of it. No issues works fine in cc4. However when exporting the fbx the morph is not there in maya nor unreal. Am i missing a step? Or is this a limitation of using cc4's base model?

Any morphs you import and create in CC are only for internal use.
Those are static morphs, which capable of conforming any cloth item character is wearing and scale bones.

If you have iClone/Morph Creator, you can make Body/Cloth baked morphs which would be exportable.

Or you may add body morph to face profile as custom blend-shape in CC and import cloth morphs separately (if required).
Those could also be exported.

Note: Those exportable morphs are only for mesh deform. Bones scaling is obviously not supported.