I’ve been calling this a torture of my own devising. Instarsia is not my favourite, though was slightly better once I switched to wrapping butterflies of each colour.

I worked a variation of my usual baby blanket method.

Begun with provisional cast on and worked interior intarsia chart section. Switched to green & picked up stitches along side & cast on edge to work in the round. Second round worked decreases along side sections to have the same number of stitches on every side. Worked 1 row of yarnovers + k2togs. 1 row knit, 1 row purl.

Then cast on 16 stitches (again provisionally) to work a knitted on garter stitch border. The last row of purl on the blanket’s edge actually hides the join quite nicely. On previous blankets I hadn’t been super satisfied with how the joins look, but I think I’ve solved the puzzle!