I have not SID on nine patch...have you thought of continuous curve? I made it a game to see if I could not have any curves left when I got to the end of the area (Not always a square). I don't use the app this lady does, but I DO plan out my quilting before I start. Enviably there is SOMEPLACE I forgot, but most of the time those are few.
https://mulberrypatchquilts.wordpres...uilting-ideas/
Someplace I have seen a video or blog post about planning out CC, but heck if I can lay my hands on it now...If I do find it, I wil l come back and post...