AgileFall does sound like an unholy mess, taking the worst aspects of both Agile and Waterfall!
However, I still think waterfall is the only approach when trying to design a hardware product. Electronics require pretty specific requirements up front before you design and order boards, obviously mechanical tooling can be even more expensive.
But... I think there are lots of ways to do quick experiments and tighten up the feedback look even with robotics or electronics. Breadboards and development kits can be used as initial electronics prototypes. 3d prints help test a mechanical concept. Within each phase of the design more experiments can be done. But ultimately the project is probably more waterfall than agile!
However, I still think waterfall is the only approach when trying to design a hardware product. Electronics require pretty specific requirements up front before you design and order boards, obviously mechanical tooling can be even more expensive.
But... I think there are lots of ways to do quick experiments and tighten up the feedback look even with robotics or electronics. Breadboards and development kits can be used as initial electronics prototypes. 3d prints help test a mechanical concept. Within each phase of the design more experiments can be done. But ultimately the project is probably more waterfall than agile!