Not too sure how much this might help but maybe this could give you something to work off of. One thing I found that helped me consciously work towards getting a noticeably better and more consistent output on my sausages was to experiment as to where I started drawing them and to take a mental note as to which approach worked best for me. This might be a no brainer to some, but it took me a while to notice that I was drawing better sausages when I would start with the inward facing curve rather than the outward one. Also maybe another no brainer to some but I didn't fully realize that rotating the page could help in this context too, making sure I was drawing in a position where my hand wasn't blocking where I was drawing helped me here if that makes sense.

How are your single arc lines? Can you do a single, confident arc while following a set path? Maybe try the frayed lines exercises, but for arcing lines (small and large). Sausages are basically a set of two arcs, but connected.

The other thing is I've found is that is seems everyone has a "Goldilocks speed" for drawing (if you are familiar with the fairy tale of Goldilocks and the three bears)--not too slow (wobbly), and not too fast (inaccurate). Just right. If you experiment you can probably find your own current, personal "Goldilocks speed."