It's pretty close to the theoretical optimum. You need 18 salts to create each output, and for 6 outputs you need to draw 108 salt atoms. Two salt atoms are available on cycle 1, and presuming you grab them and remove them two more will be available on cycle 3, and so and so forth every odd cycle. This means you'll have 108 salt atoms drawn by the 107th cycle if you never miss a beat. From there it's a matter of getting them to the output in the right form in the fewest possible cycles. At very minimum it would take four more cycles (one to pick it up, one to move it and bond it with the existing structure, another to move it over the output area, another to drop it) so the theoretical optimum is 111 cycles.

When I finished this design I immediately saw my mistake; I use my last two salts to create a death atom, which requires an additional three cycles to drop the salts, pick up the death atom, and move the death atom. In order to do it faster I'd need to use both of the last two salts as the two salts in the final output. That is impossible with the layout I have here. I'm still pretty happy with 114 cycles, though.