Today I spent some time working of different methods for attaching the modules. 

I had already modeled the wood plank design over the weekend but did not have screenshots. The plank sits inside two modules to stop them from sliding apart. The planks are not visible, but holes for different configurations are. This attachment is adaptable to different configurations of modules.

My second idea, a wood surround, works best for the triangles. It is visually appealing, but not adaptable. Customers would need to order the surround for a set configuration. The surround holds the modules together as a single piece, and then they can be removed and placed apart for individual seating.

I have not spent much time on the third design yet. So far I have a wood half-cylinder that modules with a divot could slide along. This is based on RISD design that I found which used large mycelium cylinders of different colors on a sliding base. I added a half-cylinder mycelium module that can use used to create a full cylinder, or form a longer bench when combined with the existing cube module. The slider would be a set length, so it is not that adaptable.

I plan to continue modeling different attachments, and come up with new modules and configurations along the way as well.