You're correct. Actually, we started building the first turbine w/ suppliers before we decided to commit to primarily vertically integrated manufacturing. Seeing the abysmal performance of supply chain was the main thing that convinced us to make the investment in vertical integration.
Most of "Sprint Core" parts were made out-of-house; turbine blades and compressor vanes are in-house. Next unit is 80% in-house.
I don't believe I've ever claimed 100% in-house manufacturing—that's not even our strategy. If suppliers can get the job done on cost on schedule, there's no reason to re-invent the wheel. But many times they can' move as fast we need, and that's where we vertically integrate.