One issue with Ti: Tooling costs, particularly for manufacturing skins. Tooling for shaping metallic skins to the required dimensions is fantastically expensive

One issue with Ti: Tooling costs, particularly for manufacturing skins. Tooling for shaping metallic skins to the required dimensions is fantastically expensive, which can be prohibitive for prototypes. Carbon fiber can be shaped much more inexpensively. BTW, "scaling for production" in aerospace doesn't mean a tremendous amount of units, most of the time. Lotsa carbon aircraft running around have been built in a manner not too differently from this one. So those labor costs tend to work out okay. For a while I did repair design and analysis for engine nacelles made out of carbon fiber. These were new parts, right off the production line, with various flaws that commonly happen when you make an airplane out of cloth and glue. I was amazed by how much manual labor can go into declaring a particular part flight-ready, and the financials still penciled out, apparently. We must have been well into the six figures on one particular nacelle in post-fabrication engineering analysis work, just to show that the flaws had been repaired adequately for entry into service.