I wouldn't count all of these as ticking time bombs since a ticking time bomb is usually a looming threat that threatens almost the entirety of the good characters in that arc. It doesn't typically really include actual people like Big Mom imo, only exception is rare cases like the hunger pangs in wci
Time Bomb is basically a Problem that if not Solved in time, causes "Game Over",
Don't compare them to Birdcage, because Birdcage was Unsolvable, it was tied to Doffy's Defeat,
But Defeating Kaidou wouldn't solve those Nine Problems if those Nine Key Figures didn't intervene,
For example, would Defeating Crocodile have Disabled his Time Bomb? Ofc not,
Arabasta's Birdcage instead was the War that was happening, as soon as Crocodile was Defeated, it Rained & War Stopped,
So, Time Bombs basically have their own Sub-Plots, separate from Defeating Main Enemy & his Commanders,
I'm simply pointing out that Wano had Nine such Sub-Problems, and each one was Countered by One of Nine Figures who Joined in Act 3,
Foreshadowing that in Final Saga, We will have Nine "Game Over" Scenarios that need to be Stopped by SHs,
In Elbaph currently, if Imu & her Commanders are Defeated, all Problems are Solved Instantly, so They aren't Arc's Time Bomb.