Can't you request a separate patent if you're making substantial improvements to it? No idea if that's what happened here, but I'm just saying it's not surprising that a new patent would reference old patents.
I assume that for most things the current tech is durable enough. If it needs to be more durable, going with cast, forged, or even mim metal instead of geometry changes would be better. If you really want geometry stuff, just design one yourself. Use three nozzles - a primary vertical down, two trailing secondaries opposing each other on slightly doward angles and slightly above the primary. Put all the nozzles on the same head but with steppers driving eccentrics to adjust height for each nozzle for areas where only a combination or single nozzle can be used. You'll effectively build a three layered wall with offset layers. Simultaneous printing allows better adhesion by row, and the staggered design provides increased interconnectivity between each strand.
I assume that for most things the current tech is durable enough. If it needs to be more durable, going with cast, forged, or even mim metal instead of geometry changes would be better. If you really want geometry stuff, just design one yourself. Use three nozzles - a primary vertical down, two trailing secondaries opposing each other on slightly doward angles and slightly above the primary. Put all the nozzles on the same head but with steppers driving eccentrics to adjust height for each nozzle for areas where only a combination or single nozzle can be used. You'll effectively build a three layered wall with offset layers. Simultaneous printing allows better adhesion by row, and the staggered design provides increased interconnectivity between each strand.