But becasue the character shet shows discreet interverals of something doesn't make it True. the mastery Stat for example shows its effect to the nearest interger, and we know that isn't being rounded at all in practice.
The tooltip is rounded, but the Mastery stat isn't, right? I know it's kind of a shitty tooltip & they should definately put in the extra digits, but I assume they did it because they needed to explain an entire mechanic in a single tooltip. Also, Mastery is the only tooltip that does tell you it's exact conversion rate, so you do know what it should be ... sorta ... if you're older than 6.
Also, the thing I said about Expertise doesn't matter with rounding, from 2.75% -> 2.96% isn't rounding, it's being correct