update v2.1: See https://www.printables.com/model/380870-customizable-honeycomb-storage-wall-openscad/comments/807006 for more info about the fix.
I also configured the default size to be a 10 x 10 grid that fits a Bambulabs printer.
update v2.2: Tried to fix prusa slicer errors, according to this comment: https://www.printables.com/model/530149-customizable-honeycomb-storage-wall-openscad-v21-b/comments/1538988
The author remixed this model.
I've added @fsnuxer's fix, so that it now seems to be 100% the same as the original.
Various fixes and improvements.