I've used Matilda's own pure wool batting and it is heavier and bulkier than cotton. The quilt is also the biggest entire quilt I've attempted on my poor old machine and is really putting pressure on my shoulders. I've only SID one and a half diagonal seams so far as I have to stop and readjust the quilt every three inches.
The problem with SID on the diagonal is that at some point, you seem to have most of the quilt stuffed into the harp space. I've only go just under six inches harp space, so that makes it difficult.
Here is a picture of part of the quilt stuffed in the harp space.
Here is a picture of my excellent visibility while I attempt to stitch in the ditch.
I decided I didn't want to buy any more fabric for the dresden plates, so used the sheet I bought for it which is a jacaranda flower colour. This colour doesn't exist in the dresden blades, but I still think it looks nice. It's not as blue as this photo, but has more of a lavender tone.