For anyone else looking, use duplicate your top bottom render, use frame to crop and reposition (so you ahve a left eye and right eye) select those 4 items and add stereo 3d FX. Then, I grouped that, and went through regular post process for rig removal, grading and whatnot.
I can't figure out how to properly import 1:1 ratio top/bottom 3d footage! Please help. We've got the workflow from mistika VR, but what if we already have a stereo 4k image (top bottom) that we want to grade and remove a rig? thank you in advance!