From some of the Q & A, it seems material design is going to be one of the biggest bottlenecks. Making the electrodes thin enough to give enough granularity, but also durable enough to provide a strong and reliable signal for many years.
Sounds like an engineering problem the can be solved with the right mix of experts, motivation driven by mission, and limitless funding by the likes of Musk to grease the wheels of innovation in this domain and problem space.
