Allow us to buy an assistant that can be used to do tasks while you are in combat.
The assistant would be able do a task at(example numbers)
2x(twice as long) the speed and 5% of the xp
XP Boost would not affect the assistant and they are only able to be used while in combat.
So you could only use them while in combat to do non combat tasks. This would not be meant to double dip and mine 2 ores, or cut wood and do carpentry.
This could be a premium item or boss drop enabling us to passively level another task while still doing combat. The speed and xp being reduced more to make it more of a value to use for farming an item rather then used to dip into xp for 2 tasks.