Not sure I understand your sarcasm. I read the documentation, source code, handler writing guide, and issues in the Go repository multiple times over two years, and I use slog extensively. Go is my primary language since r60. I think I know how to read Go docs.

Now, please point me to the place in the documentation that says if I can or can't use a value implementing the error interface as an attribute value, and will the handler or something else would call the `Error() string` method.

My definition of "supported" is simple – I could pass a supported value to the logger and get a reasonable representation from any handler. In my example, the JSON handler does not provide it for the fmt.Stringer.