I share your skepticism about Titanium as a frame material, both in terms of comfort claims and tube shape limitations.
However, you might find this interesting -- No. 22 bicycles has a (very expensive, prototype) titanium aero bike: https://22bicycles.com/products/reactor-aero . It hasn't actually seen a wind tunnel but at least it looks like an aero bike and they're talking about putting it in one. It is made using 3d printing (additive manufacturing) at least in part.
> Pricing for the final production version has not yet been finalized, but we anticipate a frameset (frame, fork and headset) price in the range of USD $10,000 to $15,000.
However, you might find this interesting -- No. 22 bicycles has a (very expensive, prototype) titanium aero bike: https://22bicycles.com/products/reactor-aero . It hasn't actually seen a wind tunnel but at least it looks like an aero bike and they're talking about putting it in one. It is made using 3d printing (additive manufacturing) at least in part.
> Pricing for the final production version has not yet been finalized, but we anticipate a frameset (frame, fork and headset) price in the range of USD $10,000 to $15,000.