The Challenge Log: Adding "Challenges"

I love the concept of the Challenge Log; I do believe there is room for improvement, especially on the "Challenge" part of it.

Imagine each week, in addition to resetting your static challenges, it also introduces new challenges directly related to Boss encounters. These challenges rotate each week to a new random set of say, 5.

Examples
"Wetter as it dries" : Defeat Leviathan while he is a performing a slam on the boat.
Reward: +Grand Company Seals, +Gil.
Extreme: +Tomes, +Additional Gil, +1 drop (A randomized item from Leviathan's Loot Table + others, such as a stock of resources, potions, Tomes)

"Common Cold": Defeat "That second boss in Admapor City that I don't remember the name of" with the party having sequential stacks of the taunt debuff. (1, 2, 3, 4 for example)
Reward: +Gil, +Myth tomes.

While I would welcome more challenging challenges, complicated boss kill requirements are simply absurd.

They should add a special reward for 100% all challenges in under a week regardless. Something useful, not just gil or exp.

...An i50 ring that offers 3x atma droprate while under sanction.

One can dream, right?