Ok, so, I cast a few hundred Ice Lances - and I didn’t see any Crit’s that are outside of what I would expect with a 4% per rank crit multiplier. It is definitely higher than a 5% extra crit multiplier (effective 2.5%), since I did get some crits that are outside that range.
So, I’m going to stick with 4% per rank for Let it Go, as the tooltip implies. I don’t know how the spell data mined from the client can be different from what the spells actually do… that’s beyond my knowledge, since I’m not the one that mines the client.
I noticed this with feral druids and ww monks as well. The buff to tiger palm, blackout kick, and rising sun kick mentioned in the notes is definitely in the game (I have a 110 monk and tested it as well), but the spell data was not modified to reflect it. Feral druid damage was buffed by 4% like the patch notes said, but the spell data doesn’t reflect that either.