There have been Discussions on Facebook Theta groups
about stitching errors on panoramas with more than two circular images
Check this Example Panorama, winter 2016-12-02
I only find a little on the N image up
I think a 4-8 K Theta should have 3-4 maybe 5 lenses
to perform High Quality Video and Equirectangular Panorama without Chromatic Aberration.