I've done it...
Some of the levels were a pain, like beating hard mode for all of the Ash Salt boss fights, especially Drifting Time, even with Timekeeper, and some of the logbook parts took a while to get, but I've completely 100%ed timeline of fate, at least until the next content addition to it
Used Sugar Swan, Millennial Tree, Awakened White Lily , Timekeeper (after I got her, Eternal Sugar before I did) and Dark Enchantress to do it
Pretty much all of the Ash Salt boss fights require Timekeeper, especially Drifting Time, or at least they're made easier with her, so if you don't have her, hire her for those levels, and if you do have her, be kind and hire her out, especially if you have her built properly (full cooldown toppings with full light attack beascuit seems to works the best for most of these levels)