Skills are a mess with MW, because players don’t see the decimal. You kind of take a chance on it attempting to get another full +skill to make it apply. Partials don’t.
Current theory is that MW applies to the base value only (outside of GA, even) and must be greater than 0.51. So one MW crit on a +2 wouldn’t result in a +3 when you add in the 5% per level, but two MW crits should.