nothing gained...

I calmed down, thought some more and figured I’d be further ahead to actually cut my new shape out of another fabric and baste it in place to see if it worked. It would be easier to fine-tune the knitted piece that way as I did want to be able to sew it in place with finished edges without having to resort to serging alterations, or worse, having to re-knit because it was too small!
So glad I did! With the pieces basted in, I could try it on and adjust little bits here and there  to get the fit I wanted! Pretty pleased!
BTW, another deciding factor on the yarn, I had a leftover part cone of WCD in chocolate (234g) that should be just the right amount – didn’t want to break into a full cone of something for this!