These are convenience methods but take up a large fraction of the API surface of this class.

It makes sense to keep the ParseResult.matchedOptionValue methods (TBD with or without defaultValue parameter), but the rawOptionValue methods add a lot of (11 out of 35) methods while it is not clear that there is a need for these methods. Wouldn't client code be more interested in the typed results?

Clients can get the string values by using ParseResult.matchedOption(name).stringValues() at the cost of either a null check or a preceding call to ParseResult.hasMatchedOption(name).