I think I would also stitch fairly close to the subject in the block, that way it makes it stand out more.
I generally try to remember to put the label on the back before I get to that part of quilting. The one and only time my mother had a quilt professionally quilted, she wanted the label before she started quilting so she could quilt it in. Reasoning was as mentioned above, with thefts of quilts, would be hard for the thief to take off the label before unloading. Also would deter what that nervy lady did as in regifting as her own.