Fair enough. My thinking--and this is mainly in regard specifically to KW suits--was that a completely unstructured shoulder would call for a similarly relaxed, soft construction throughout the chest and quarters. Hence my suggestion that the soft canvas (note: still full canvas, just a thinner piece of canvas) or unstructured might be the better option to go along with unpadded shoulders. Is this not at least somewhat logical in theory?
But having never owned a truly unpadded (natural shoulders) jacket, I did acknowledge that it might be totally fine in practicality. I'm probably just overthinking it.
One of my favorite casual jackets is an Eidos soft shoulder, full canvassed, cobalt blue hemp-wool. Unbelievable weave. I think fabric is by Tallia Di Delfino.
My lone Formosa has a natural shoulder (so, not unpadded) and definitely looks more formal. I think that's actually their house style and I'm not sure they do a totally unpadded shoulder.