I don't know if this is useful or not, but some guy claims to have come
up with something similar to the infamous "Starlite"
ablative/insulator.
As it is, I have no idea how it compares to existing established
ablatives, but there was a lot of buzz about Starlite a few years ago.
Here's a youtube video describing the non-scientific properties and a
method to make it:
https://www.youtube.com/watch?v=aqR4_UoBIzY
Historically, here's some background info on Starlite:
https://www.youtube.com/watch?v=10C5oQiUU_U&t=236s
https://www.youtube.com/watch?v=wxY8IXccik4