Okay, here is some Super Luck information:
For the record, me and Peterko tested critical hits in general 2 years ago. I still have the results of the tests we conducted:
Non-High Critical Hit move - Out of 100 hits, 7 were critical: 7/100 = 7%
This is close to the normal 6.25% rate, i.e. Critical Hit domain 1.
Night Slash only - Out of 120 hits, 12 were critical: 12/120 = 10%
Razor Claw - Out of 336 hits, 38 were critical: 38/336 = 11.31%
Scope Lens - Out of 128 hits, 17 were critical: 17/128 = 13.3%
Super Luck - Out of 120 hits, 13 were critical: 13/120 = 10.83%
All of these are close to 12.5% rate, suggesting that all of these are in Critical Hit domain 2 (at that time, high-critical-hit moves being in Critical Hit domain 2 was news, as they were in domain 3 prior to DPP).
Focus Energy - Out of 406 hits, 101 were critical: 101/406 = 24.88%
Shadow Claw + Scope Lens - Out of 120 hits, 25 were critical: 25/120 = 25.83%
Night Slash + Super Luck - Out of 120 hits, 32 were critical: 32/120 = 26.67%
All of these are close to 25% rate, suggesting that all of these are in Critical Hit domain 3 (at that time, Focus Energy adding 2 to the Critical Hit domain was news, as it only increased it by 1 prior to DPP).
Focus Energy + Scope Lens - Out of 256 hits, 97 were critical: 97/256 = 37.89%
Night Slash + Super Luck + Scope Lens - Out of 192 hits, 58 were critical: 58/192 = 30.2%
Super Luck + Scope Lens - Out of 296 hits, 93 were critical: 93/296 = 31.4%
All of these are close to 33% rate, suggesting that all of these are in Critical hit domain 4.
Interestingly, Super Luck + Scope Lens hit with a CH more often than Night Slash + Super Luck + Scope Lens, but we thought that this was just good luck, and we concluded that Super Luck + Scope Lens should have been at around 25%, while the other one should have been at around 33%.
From the data above, it is clear that Super Luck is only increasing the Critical Hit domain by 1.
So Bulbapedia and Serebii are not just wrong about Super Luck, they are wrong about Focus Energy as well.