I think most people can agree that the memory gathering requirements are kind of steep. Even if enriched memories count as 2 for the purposes of charging the engrammeter, 500 each time for 15 times for a total of 7,500 collected memories is longer of a grind than most people would find feasable.
Some things that I think could alleviate this steep requirement and streamline this miniquest:
-Have the engrammeter automatically charge from the collected memories while in a player's inventory
-Reduce the memory requirements from 500 per full engrammeter charge to, say, 250 or 100
-Allow the engrammeter to store all required memory charges past the first full charge, i.e. rather than stop every 1x number of gathered wisp memories, stop at the full 15x as an overcharge.
And for players who already completed the miniquest, allow them to collect a reimbursement for the memories they'd collected and used to charge the engrammeter, whether it be in XP or in a chosen type of divine energy. This reimbursement could be collected from either:
-The engrammeter itself
-||Kharshai||, the guy you start the miniquest to begin with.