I used 8X of the player trays from https://www.thingiverse.com/thing:2390899. If you have more then 8 colors they won't fit in the box with this tray and
...Show more those holders.
This is a square that will fit in the corner and hold most the cards. Encounter, flair, defender, and destiny cards. Some others like tech and optional cards won't fit and I have just bagged them separate. This should fit expansions and sleeved cards for the most part. I have two expansions and penny sleeves.
You can download the scad file and adjust/add/remove compartments. You can also try reducing the wall size a bit to get more space and clearance but the tray may be to fragile then.
I updated with a solid block in the corner as this extra space wasn't usable and filling it uses the same material and prints faster.
