Lovely stuff! I wont post it into The BOM HOF until its a finished piece, OK?
BUT remember the 1/2 squares of the twist will only be on the top and bottom of each block, I think you may have those on the side in some of your blocks!
Its a bugger to figure out until it clicks into place...
Yes, If I were to use a feature fabric, in say Red, I would make the twist a (much) darker red or Red pattern.
I think the fact that the blue was 'darker' than the red is why the second pic works better!
With the Spiral Child, I chose a batik that had a lot of the colours I was using for the twist.
And, as you can see, in the B & W version I have chosen a black with white outlined stars for the twist,
so not quite a solid...
but as ever there is going to be a twist on this particular Twist and Twirl