We've had that as a enhancement request for a while now, just hasn't made it into a product. Have your local SE add that in through the the normal enhancement process. If we get enough of them in, then it should be easy to push through.
You can open a case with F5 Support and ask for a request for enhancement (RFE). If an RFE ID already exists your request will be attached to it. Else one can be created. Once you get the RFE ID, you can escalate the request through your F5 account manager.