Other thoughts I've had recently:
Since the working needle sets the gauge, and right now one of the things that is slowing me down is moving stitches off of the stationary needle, why not use a smaller gauge needle on that side? Just go down a size or two. I've been getting better about not knitting too tightly (otherwise known as figuring out how to make the Addi Turbos go fast), so this is becoming less of a problem, but it would still be fun to experiment with. This would mean purchasing a set of Denise needles or equivalent.
It should also be possible to develop an inexpensive swift substitute. I believe that the adjustibility of the swift is primarily to go in the opposite direction, to turn balls into skeins. I think it would be an interesting engineering challenge to come up with a swift made out of off-the-shelf parts, that could be made for $20. Since the manual ball winders are sometimes available on sale for under $30, an entire setup could be made for under $50. This will especially benefit people that don't live near yarn stores, and need to mail-order yarn. One initial design is a cone on a lazy susan, where the skein of yarn just falls to the correct circumference. Depending on the variability of size in skeins (which will set the height of the cone), there might need to be some weights inside to adjust the inertial moment of spin. If people want to go from balls to skeins (say for dyeing), that might still be possible by putting a "collar" around the cone at the desired circumference.