With as many heroes as we currently have, I suggest that the memory market be expanded beyond the current 8 slots per day. Perhaps 12 to 16 slots?
And/or a system to mark certain discs as preferred or to buy mission speed ups for memory market tokens would be very welcome.
It takes too many refreshes just to get options for the hero/disc you want to improve.
You can prioritize the disks you want by leveling them up higher than level 7, and leave the rest of the disks at level 1 - this is minimal cost in disk power and since you are prioritizing the disk I assume you would like to level it up further.
Although I do agree with the number of slots compared to the number of heroes currently in the game - a nice present would be to receive one free refresh a day (similar to normal market) by the team for memory markets 