I really like @JosephFisher_411296's remix to integrate the insert with the box. I hated that the grooves for the box were empty. This isn't really necessary for the box to close. However, it adds a nice accent if it's printed in a different color than the box. Printed mine in TPU, can't guarantee it'd fit if printed in a rigid material.
The author remixed this model.
Remixed the box seal from @Samael_ to fit the remixed box of @JosephFisher_411296