I thought some may be interested in my latest post: http://photography.grayheron.net/2019/12/theres-close-and-then-theres-venus.html
What a strange lens! Cool mini tutorial, I didn't even know such a lens existed. What's the intended normal use? Large backgrounds on small subjects?
Prime use for the the lens, if you forgive the pun, is to achieve macro images of subjects in their environmental setting.
The manual focus stacking is a niche capability.