I have good MNK news regarding Chimera. You don't have to throw the fight after 25% if Chim is tanked in the NW corner (which I understand is common practice).

There is a safe zone on the left side of Chim, up against the wall, which places you out of range of Chim's swipe attack and the constant sandtraps. Slide along the wall and lock target; you'll face Chim and hit from the left. From here you can time your Pounces after the sandtrap fires, run back to the safe spot for a Demo/SP, then buff up in preparation for a Blindside-HF/DK from the rear after the next trap fires. You can even Hundred Fists from here if Chim is feeling generous.

Voice of the Ram, Voice of the Dragon and Breath of the Dragon remain a hazard as much as ever, so fall back to the mages when these appear in your log. You will probably be hit by the trap, but 1500 damage is better than 2500.