First, there are now more Encounter Rate options to provide finer tuning for how often you have battles. You can toggle through the different rates using the 'Q' and 'Z' keys.
Second, the 'Q' key will raise the encounter rate. The 'Z' key nows reduces the encounter rate.
Previously, they both increased the rate and it looped back to no encounters once you reached the max encounter rate. Not exactly great. So hopefully this is a little more convenient and intuitive.
Happy learning!
Lun