Michael Zingale

particle parameters should also be moved into `_cpp_parameters`

renamed to reflect that gravity and diffusion have been moved already

radiation is difficult because a lot of the defaults are dependent on if-tests in the code that are only known at runtime.

it looks like particles are all done

to be clear, I think we are second order accurate with or without it. If it works well, then I am happy to have it in, but it does not...

I'll update the submodule

https://github.com/AMReX-Astro/Castro/pull/2275

Note: since none of us really run on CPUs anymore, this has not been much of an issue, but it would be good to have full CPU support in this...

it's one of those "we'll know it when we see it" situations, so I am not sure I can point to anything, and in fact, all may be well.

With the fourth order code path, it is not as easy.