We don't need to expose a new API here. Instead, we need to fix the SmartEnum.List. Right now, it reads from the _fromName dictionary and creates a brand new list for the output.
That's unnecessary, we already hold an _enumOptions field which is the list of all enums. So, we need only the following fix

public static IReadOnlyCollection<TEnum> List => _enumOptions.Value;

@fiseni, you are actually correct! I completely overlooked the _enumOptions option.
I'll go ahead with it if that's alright with you, @ardalis.

@akarboush @ardalis
There is more to it. I created issue #521 describing the details and the proposed changes.

Done