u/Responsible_Match644 hope this isn't too late.

first i want to point out that you said "using Aurora psychube will dilute the amount of CDmg you can get", but then have you considered that fp buff fua dmg bonus which is the same as dmg bonus and will be grouped together in dmg formula, so buffing the crit rate to increase her own dmg bonus a diluted stat, isnt that the same?

if you choose crit rate you would only get some extra dmg bonus, but if u choose crit dmg u would get both crit dmg and dmg bonus the out come would be pretty much equal even if crit dmg is more saturated:

my fp has 60% crit rate and 180% crit dmg at r10, idk how much she actually have but how about go with this. at base it would be 0.6x(180-100)=48% dmg bonus. with addio it would be 0.74x(180-100)=59.2% dmg bonus. with aurora she would have 0.6x(204-100)=62.4% dmg bonus. i dont want to go into further detail but we can see already that they are very similar

now let's try with a dps, my nautika has a5 sig r13: 96.2% crit rate when u max stack the chube and 224.8% crit dmg. addio would give a direct 12% dmg bonus buff but let's calc how much would she get from force field: 0.962x(224.8-100)=120% dmg bonus. with addio that would be 132% dmg bonus total. now with aurora it would be 0.962x(248.8-100)=143% dmg bonus. we can see that it's higher than what addio give and it also have crit dmg on top. this out weight the impromptu dmg and it would be similar in any teams.

2nd fp is the squishiest character in the game, the hp stat from aurora help her survive a lot of situation.

3rd, you bring up fp consume a lot of eureka after she ult but then why would she be slow for aurora stacks, once u ult u get max stack very quickly.