It'll be interesting to create a "reverse-LEGO" System, where System parts can be used to repair non-System products. Eventually, Ship-of-Theseus style, products would end up becoming entirely made of System parts as their old ones break and are replaced. To this end, you have to make sure the System is interoperable both with itself and with pre-existing products.
Further, it would be best if the System were not only easy to manufacture, but easy to acquire resources for. This is a big part of the #Junkpunk aesthetic, going out of your way to reuse pre-existing material. In the context of our System, this might involve anything from collecting screws of standard System size off non-System products, or searching for plastics to turn into stock for 3D printing. 3D printable printers and recyclable stock would be a HUGE jump towards making this a reality. #solarpunk