After having lunch, Chris stayed behind and prepared cake for the evening. He still has a lot of time before the dungeon becomes available for grinding. waiting for hours would become a pattern for him for now and also in the future.
In future, as he ranks up, the waiting time would be longer unless he obtains a mana source for the dungeon so that it would be able to create monsters faster or gain a higher level attribute dungeon. This was something he had an idea about.
In his past life, he got his hands on a higher-level dungeon, but that was when he was a high ranker. Now challenging the region where it was located would mean certain death. He might not die for real but would lose EXP and Levels as the death penalty.
He is in no position to make wasteful moves.