When reading the SAP HR docs on the encoding configuration parameter, it doesn't mention where to get the list of valid values for it. Is it the same as the JVM's character encoding list?
That is correct. The value of this parameter is used to open a FileInputStream object using a handle to the .meta file. Instantiating this object will either validate the parameter is correctly specified and is valid for the JVM, or it will throw a UnsupportedEncodingException which the driver will catch and translate into a "Specified Character Set Encoding is not supported." message. The encoding specification is JVM specific. If an encoding is NOT specified, the default JVM encoding will be used.