Run&Gun
Veteran
Some thing Ive suggested before is sony integrate thier RX0 into or ontop of the fx/fs (?) This has a FF20mm (15S35) FOV or something and could be attached to a sony camera to roll and go into the EVF when a button was pressed - could even write to the main card.
WIth that the 20(s-35)-xx lenses would gain more attention.
About 30 years ago or so, one of the consumer manufacturers, I believe JVC, had something very similar, with a small camera on the top handle of the main camcorder.