I haven't touched R3D_Printing's original model, which I find works very well - even for plants ready for new pots :).
I've created an additional connector for the edges of your construction - where two of the points in the joint are single-wide. The modified connector supports this type of joint better than using the original connector.
In the close-up photo, I've slapped a connector on the front of the display - in order to show the connector without having to turn the display around. Maybe I'll work up a multi-color version of both connectors.
[note: I've used the same license that R3D_Printing used on the original, but I grant R3D_Printing the right to do whatever they like with this connector design since it is a derivative of [her/his/their] design.]
I re-created the original connector in OpenSCAD then changed a few parameters to reduce the width of two of the arms in the connector. I've noticed that there are lots of interesting things you can do with 120-degree angles, so thanks for the inspiration!