I used a 'smocking machine' once. It belonged to a college. The problem was that it twisted, so the lines did not come out straight, and also, you could only do a panel, as the bottom of the fabric did not go through , so you were limited with what you could do.
I preferred putting the gathers for smocking by hand, and made a number of baby dresses with smocking for my girls, when they were small. I think I had Simplicity patterns, which came with the transfer. After it stopped working I penciled in the dots with a ruler. That is time consuming, but it does work.
PS You are evil, I just got lost in smocking for a bit...