I think the proposed "new" signal in the first post is unnecessary and could be potentially confusing....... especially if ever used on group dive with others who may have not thoroughly discussed and agreed on the signal.
Isn't this true of just about any sign?
My wife and I have been taking classes to learn American Sign Language, our daughter who recently moved home from university just started a beginner class....I look forward to the next time we dive together as our ability to communicate should be significantly enhanced.
-Z