This explains a few things…

The officially-listed boosts given for Defense, Acc, Resist, and Damage inspirations (25, 33, and 55%, by size) are, generally, nowhere near the ‘real’ numbers.
Arcanaville (who figured it out and pointed it out to the Devs, who hadn’t realized it:)

Although I cannot say she was the first to put it this way, it was Kali’s multiple reports of lucks “not working until enough of them were used” that got me thinking that they might not have been broken, just weaker than advertised. Which caused me to run specific tests looking for the ramp up/ramp down behavior, which I was able to reproduce consistently in at least one instance.
The question I posed to pohsyb was this (paraphrased): are lucks modified by the AT scale modifiers, in such a way to reduce their strength, because they appear to me to be working at lower than their advertised numerical value.

The real numbers?
S – 12.5%
M – 25%
L – 33%
S – 7.5%
M – 18.75%
L – 37.5%
S – 10%
M – 15%
L – 20%
S – 25%
M – 33%
L – 50%