I was thinking it might be possible to have multiple dies on a single head.
So with a switchable die, you could extrude a single bead, or several beads in parallel with a gap in between, or several beads so they coalesce (basically it's like doing wide tapes.)
If it can be done, it could be quite a bit win because the amount of material deposited per second goes up several times, and could be a huge win for solid volumes.
Thing is, the die switching might be only one extra axis, or less; whereas multiple heads need an axis each.
I was thinking the die could be arranged as a drum or a disc, and you'd have seals to connect the particular die to the output of the normal hot end when it was positioned appropriately.
