Took the NCEES practice exam this last weekend and tried using only the handbook.
Some of the formula forms are super weird, and I did end up having to look up a few things elsewhere because they just aren't in the handbook.
Things that stood out to be missing to me:
Wattmeters, ampmeters, and voltmeters -- which are involved in several problems
mho circles
symmetrical component / fault analysis - are they expecting us to derive the formulas for like a 1 phase to ground fault via the tiny diagrams on p66? cause that's a LOT - i mean i could do it with practice, but I like using different diagrams, and that's SO much to memorize for all the different fault types
it's slim on fault analysis
I had a hard time with a parallel transformer problem using just the formulas provided in the handbook because they weren't totally twins and the handbook doesn't have additional information on that type of problem. I ended up referencing my personal notes on the subject.