IntellipromptMemberList and Allowed Characters

I have multiple triggers that ultimately result in the MemberList displaying to the user. Certain triggers result in the standard characters being allowed. For one trigger, though, I would like to add the '.' character to the allowed character list. The problem is once this is changed for the MemberList for that instance of SyntaxEditor there seems to be no way to remove it. CharClass contains an add method but there is no remove method (for the AllowedCharacters property of the MemberList class).

Am I missing an obvious way to do this? If not, may I request a remove method be added to the CharClass class? Thanks much.