Why must all improvements fall under the umbrella of "while using Composure"? It's ridiculous I tell you. We don't need to tie every modification to the job to Composure. If we do that we may as well make all the changes independent of Composure because it will simply turn into a great big "Make Red Mage function properly" button.

</rant>

More on topic, I'm going to echo Doom's sentiment. That sort of change would require delving into the core code of the combat engine and SE is extremely reluctant to do that. Even if they wanted to, I'd wager they don't have sufficient staff on hand that's familiar enough with that part of the code to untangle all the spaghetti code involved.