As for @JeremyKREBS_559468's design, you may need to remove the carboard organizer from the box, fold the carboard around the printed organizer before reinserting it into the box. However, the fit could be better with thinner sleeves or without the carboard side of the organizer.
Also, cards may be a little difficult to catch since you cannot pinch the pile from the sides as with original design.
Edit: Since I was not satisfied of how tight the cards were, I created a new cards holder (for base decks) to sit in the players storage area.
The author remixed this model.
Organizer for the Amalfi Rebirth boardgame based on @JeremyKREBS_559468 design adapted for character sleeved cards. Slot card has been enlarged and the external wall has been removed, so a pile of cards of approx 7.5 cm can fit into the organizer.