Is it better to have multiples of certain craft essence or just put them all into one? (ex: I have 5 kalied sapphires should I dump them all into one to make a super one or keep all 5 and level them)
Depends on your line up and how rare the CE is, if you have multiple servants that can use the boosts keep them separate otherwise go ahead although in the case of 4 and 5 star CE's i'd advise waiting until you have six to MLB so that u have an extra just in-case.
As said, is better to wait till you have the 5 copies, and even then you need to think about how good is its effect. I wouldn't MLB a Kaleidoscope or a 2030 if I had only 5 copies of it for example.
I'd say it depends on the CE effect, your needs and available alternatives with similar effects.
For instance, in the current event it was more useful for me to have multiple copies of White rose to clear the levels faster and last longer in challenges. But I will merge them once the event is over or after all the challenges are cleared.
Same with petal farming: I use 4 Joint recitals (and 1 from support) for a +4-5 bonus per run, rather than just a +2 from limit broken one. But since it is actually a useful CE for my regular team, I'll limit break it after the event anyway.
All in all, judge by the effects and alternatives, maybe? Hope this makes sense :S
