Interesting article on 3D printing rockets:
No specific mention of titanium. However, the future requires 3D printing to be pushed past golfclubs and bicycle frames. What better way than to create a 3D printed, re-usable rocket industry. All the big names behind this: Chamath P (Social Capital), Mark Cuban, Standford etc:
https://www.cnbc.com/2019/01/17/air-force-grants-3d-rocket-printer-relativity-space-a-launchpad.html