Thanks! Today I've just been going mad, hopping from one fabric to another to another. My initial thought was French seams, the seams are only ⅜" so may be fiddly but not impossible.
On a good note, the pattern calls for over locking and then folding under for a narrow hem. No overlocker so I was debating what size zig zag may not chew my fabric when I figured I must have a rolled hem foot somewhere. I dig out the foot box. No rolled hem foot, but overcasting foot! Totally forgot I had that, so I overcast the challis flounce edge and then folded under and normal foot back on to sew a very narrow hem! It looks magnificent. Well it did in the semi dark. It did take forever to sew though as speed isn't a thing with that foot on.
I may try it out on the next knit I do. Foot has been upgraded to the quick access desk area.