Getting proper molds built is a very expensive up front investment when you don't know how big your addressable market is. It also impedes innovation in the ear

Getting proper molds built is a very expensive up front investment when you don't know how big your addressable market is. It also impedes innovation in the early design (which these clearly are). I'm now curious if it makes sense to build replacement pcbs for off the shelf models. I certainly have a very old trackball that I used during the mac quadra era that is fucking fantastic except for the fact that it's ADB. If I could swap out the pcb and make it compatible with qmk and usb that would be fantastic. I do know that there is a small ADB to USB converter out there for keyboards that even let you do keystroke remapping, however I'm unsure of how it deals with mouse-things. But back to your main point. I think 3d printing makes sense in this space at least for the forseeable future. In the event that they make a 'hit' input device, once the design is refined a modest injection molded run of the case seems like a grand idea.