The increases make a nice thumb gusset. The stitches are on waste yarn waiting for me to pick them up and knit the thumb. But I'm not going to finish this mitten.
So I started yet another one and am knitting with 5mm needles and 4.5mm needles for the braid. The resulting fabric is not as stiff and the mitten is the right size. If I were to modify this pattern for 4.5mm needles, I would add extra stitches on each side and some other decorative element for the back of the mitten.
However, once I am finished this pair, I'll write down the mods I want to make and pick up something else to knit.
Enough is enough.