Not sure I completely agree as you often use only a small part of a library

This sounds pretty easy to hack together with 10s of lines of python

well he certainly mentions a result where if there is an everywhere timelike Killing vector field (+ some other assumptions) you can prove that Hawking radiation doesn't occur and that does not include for example the Schwarzschild solution because the Killing vector field partial/partial t becomes non-timelike on the horizon.

So for example if you take a dead star in a vacuum with nothing else in the universe (and make certain technical assumptions) then you can prove that the star does not emit Hawking radiation. That's quite a strong result, and certainly does make the result seem shocking.

I'm not sure what more you want from him, there are many papers and even a textbook linked?

It's bloody John Baez, the man knows his stuff.

On you actual point, it is shocking because its claimed that baryon number is not conserved without black holes getting involved

Does this support time travel queries?

Does it support reading everything from one snapshot to another? (This is missing in Athena)

If yes to both, does it respect row level deletes when it does this?