The Leveling Calculator returns (when searching for +/- Lv280) results with way too high EXP values for the mobs in Witch's Wood.
Example:
Witch's Wood: Area 1
- Eerie Scarecrow (Lv 183) EXP: 8.547*
- Bayaga (Lv 184) EXP: 6.270*
- Entry (Lv 185) EXP: 6.412*
Areas 2 and 3 are affected too, but I didn't check the EXP there.
*Including Daily EXP Gain Bonus +50%