I selected the dual extrusion configuration as I am personally interested in mixed material hybrid models (such a solid core skeletal structures encased in TPE plastics). At the same time, this is indeed my first printer and I've added to the learning curve. I've experimented with dual extrusion virtually and established workflow up to the print process in the meantime. That being said, the configuration for dual extrusion on the BB is still enigmatic and perhaps a bit WIP as indicated by the E3D guys. Few questions for the E3D guys: Any photos or previews to how this extrusion system will look/operate? Will there be manufacturing delays for those who selected the dual experimenters kit due to unfinished/unvalidated extruder design? If there are delays, wouldn't it be better to get single extruder configs in backers hands instead of holding up the whole shipment?