BTW
You can already do something very similar to this using an Olympus x0.8 wide angle adaptor or a Century Optics x0.8
Centry Optics glass is stunningly sharp mine has a 72mm back so it work on most lenses
or an Isco or Schneider Magna Com Progection lens focal length converter
You dont get the faster F stop BUT you do get a sharper wider image
50mm becomes 35mm
35mm becomes 28mm etc
The Schneider and Isco Magna Coms are superb stunning hi end cinema glass they cost 1000s of Dollars new but I got mine both on ebay for $80
(Kubrick used Kollmorgen Magna Com focal length modifer on the front of his Nasa lens to make a 50mm lens into a 35mm )
trusy me the Schneider and Isco Magna Coms are even better than the Kollmorgen version which as a 1070's lens
The Schneider and Iscos are modern new stunning glass.
I use these on my Tecnoir Cinema Rig in a similar way to how I use my anamorphic lenses
The same adaptors work on the Magna Coms