I saw someone mention this in the main forum, so I made a quick submod for it.
Client States and satraps will yield unto you their levies once more. Be warned, as this may allow access to reform units before reforms actually occur. I haven't tested this extensively, so let me know if it has problems.
https://drive.google.com/file/d/0B5a...ew?usp=sharing
Again, thanks to Dresden for pointing out how to do this.