@Kelly that pierce is beautiful, I can see how kerf bending works we for that. In this case with the smaller radius it seems like you would have to do it more like a segmented bowl where you cut completely through, unless the cuts were really thin at the bending point (essentially wedge shaped)? Or were you thinking about doing a hollow design, like inside and outside pieces of plywood (kerf cut) with end caps?
I don’t have a great answer, rather an idea that might partially work. Perhaps you could make it similar to what
@Martin Roper shows in his post. Use 1-1/2” to 4” segments (from front to back). Run the grain vertical on the sides and horizontal on the top. Then, make the corners like a box joint, so curved corners would be built in the top of the first segment, sides on the second…and so on. That would allow you to sculpt curves in shorter segments. The trick would be getting the inside curves sanded flus from segment to segment (unless you can make and assemble them perfectly…something I could not do). Maybe you could use dowels between segments to help keep them aligned. Anyway, this would be a strong interlocking design that would allow you to use a soft wood that would be easier to work with.
Good luck, keep us posted.