Add recent notes e.g. for #1123, #1085, #934 which could use some testing.

(@madsbk I note from the TODO list below that a next step would be an update to the tutorial with meta_array)

TODO:

• Add unit tests and/or doctests in docstrings
• Add docstrings and API docs for any new/modified user-facing classes and functions
• New/modified features documented in docs/tutorial.rst
• Changes documented in docs/release.rst
• GitHub Actions have all passed
• Test coverage is 100% (Codecov passes)