[jauntywundrkind]

Unsurprising to me. Instead of ablative self-destructing tiles, they are trying to make survivable heat plates. This is such an extreme job, has to endure so much the brunt of this crazy job. Experimentation is required to see what you've really got, as well as assess what else might be possible.

[s1artibartfast]

Exactly. The current tiles will not work and have the potential to kill reusability for the upper stage.