We do a lot of rolled hems on all sorts of fabrics. We hand roll them as we find it's more acurate because we can see the fold and stitch line. Rolled hem feet are an obstruction to viewing and are fiddly to feed fabric through. We find 3 - 10 mm a reasonable hem width and we match the width with the type of fabric.
The machine has 15 needle positions, so getting the stitching in line with the fabric edge just needs setting up for the particular fold.
We have techniques to do this on the round as well, producing an even rolled hem without puckering.
Suzanne creates with textiles, and is happy to work with you, to create your products.