[Squeakypig]

One possibility that people haven't mentioned here is the multi-bot (besides the Octo-254 previously mentioned). It is very possible to have 2 separate devices connect with a tether working together to either double stack or one stacks totes and the other tops off with containers. This sort of design is either going to take the world by storm or crash and burn. No in betweens for that design in my opinion.