General

Diligence and Spell Trace Experiments

Results:
406 slots I scrolled with 70%s while not in the guild.
If diligence did not affect the rate, it should be 95%.
Not a single slot failed.
The odds of this happening IF it's 95% are about 9 in 10 billion, roughly rounding to 1 in a billion. (if you think that's still too large of a chance for error, I'm willing to do another 203 slots for a roughly 3 in 100 trillion chance if they all succeed, too)

Therefore, I conclude that diligence does affect spell traces, and those that claim that they have failed a "95%" spell trace with max diligence are mistaken.
I also did a test outside of fever time, with guild skill on 207 slots (203 + 4 times where the guild skill saved the slot).
The results were 170 successes and 37 fails, putting the rate at 82.12% for the 70% option with max diligence and guild skill.
The predicted rate would be 84% with max diligence DID work and a 74% chance if it didn't.
Statistical analysis gives a margin of error of 5.22% with 95% confidence. The margin of error rises to 6.87% with a 99% confidence level. The predicted success rate of 74% falls outside of this margin of error.

I will do another round of this type of experiment after fever time.
Here's video "proof" of the experiment with 70% traces not during fever time.
https://www.youtube.com/watch?v=f5OHBSuWMUk
(warning 30 minutes of very boring scrolling on 1x speed)

The other video "proofs" will be uploaded as well. (just posting for the naysayers that don't believe me)
No fails on 70% trace + max diligence + no guild + fever time part 1:
https://www.youtube.com/watch?v=q4DzaSvsxIo
(video still processing at this time, again, about a half hour of boring scrolling on 1x speed)
part 2: https://www.youtube.com/watch?v=YNHrdL0x8L4
(again, still processing and more scrolling on 1x)