Logically every event, which bases on killing ingame monsters could, be implemented and/or enhanced using "Hero Trial".
For instances they could replicate the current quests as daily "Hero Trials":
- Kill 20 Sunwa
- Kill 20 Outlaws
- Kill 20 Lame Rega
- Kill 20 Super Rega
Each quest could reward ten Dumamond and instantly one layer of randomness is removed. The point is, they do not want to.