Quote Originally Posted by Cheesegear View Post
Can they read?
Can they write?
Could a Drow Undead use Drow Sign Language?
With the intent of the rule being to prevent two-way communication, I think that's the limit to consider.

"Does this enable two-way communication without the need of additional features or spending resources?"
If the end result is you are getting around the limitation without needing to spend or invest in anything (for this discussion; the class levels you have count as investments) then the original limitation was pointless.
Like having languages at all when so many games just have everyone understand common.