Even though Aaron learned that the meditation chamber would not be of much use as of now, he was hopeful that it would be one day. For now though, the other facilities are very useful.
The Gravity Room for one, increases the gravity on a person. It would burn stamina faster for a person who is in the room compared to when not in the room, but the more one works out, the better the growth of stamina would be.
It would be the same with Mana, but to burn out Mana, one has to use skills, which he can't do at this moment due to the weird usage of his skills.
He has five skills, and two of his skills are just undead-summon skills. Once they are summoned to a number, extra can't be summoned until they are dispersed.
These skills were very useful as they could be used without the requirement of mana in battle.