I'd fall off the bike or be standing on the pedals all the time. The nose of the saddle is critical for control.

I have a friend who tried a saddle that was like two kidney beans side by side. She tried it on an upright hybrid and couldn't stay on the thing. And she was a fairly sedentary rider.

Maybe if you're on a beach cruiser on smooth pavement meandering at a negative 2 miles an hour . . .