Update:
So, I tried to create an empty project an in iterations add the dependencies and configs. I found out that by changing level in
config :logger, level :info
to :warn, I no longer received Converted error :function_clause to 500 response.
I further added Logger.error(error) to render() in ErrorView, and while it still converts an error and prints it as 500.json, I at least now also get the actual error printed, e.g. FunctionClauseError with a more detailed description of what caused the error.
