The capacity of the gem bag need to be increased by some means either through a quest or a 2nd upgrade using dungeoneering tokens.
The reason for this upgrade is the rate of gem drops by slayer monsters per task (ie. Abyssel Demon) in greater in the capacity of the gem bag. and thus forced to lose resources due to a full bag mid task.
I think this would be a welcomed update that would benefit all the player base.