Yeah, the tile complexity is worrying. I hope they're able to simplify that or fully streamline the manufacturing and attachment. From the outside, the tiles seem like a Shuttle re-run, and refurbishment of those was one of the long poles in reuse.
The places that are awkward to tile are the spots that need tile the most.
Also, the ability to fly without crew and the willingness to have highly visible failures means they can actually exercise the heat shield to understand what works.