Personally, I feel like Masterful Blitz was implemented poorly in that they made it a seperate system to the Chakra system instead of layering the 2.

Here's what I would've done.
1st off, I would get rid of the crit requirement to gain Chakra and remove the Chakra gain from Brotherhood. Instead, I would tie Chakra gain to positionals so landing a positional grants you a Chakra.
Next, I would have TFC/Enlightenment act as the opener for the Beast Chakra gauge so using either skil would allow your next 3 Weapon skills to open up their corresponding Beast Chakra as they currently do under Perfect Balance. Since Nadi would no longer be tied in with Perfect Balance and thus the Beast Chakra gauge no longer be dependant on specific skills to be used, just have us cycle thru each Blitz from Elixir Field to Rising Phoenix to Phantom Rush, with each Blitz progressing in power.
Turn Celestial Revolution into a 120s oGCD attack that instantly grants 1 Nadi effectively skipping 1 Masterful Blitz attack during our burst window so as to get Phantom Rush in.
Turn Six Sided Star into a 60s oGCD attack that instantly grants 5 Chakra.
Return the positional negation to Riddle of Earth
Have Riddle of Wind gain a movement speed buff as well as a refresh on the Disciplined Fist buff.
Have Anatman be an ungraded Mantra that also offers some damage mitigation for the team if the MNK holds the position, similar to Collective Unconsciousness.

Obviously potency adjustments would need to be made to make it balanced but still, I think it would be better to keep the job engaging. Then again, that might just be the delirium from lack of sleep on my part so take from that what you will.