I have made crumb quilts. I will sew in anything I can get a seam into. If I have a little strip 1/2 inch wide, I will make 1/8 inch seams and have a cute 1/4 inch of it showing. But that piece would have to be a beautiful color that will stand out in the finished block.
I made crumb quilts for two of my granddaughters. The blocks were 12" finished and the corner stones were 2 inch finished. The corner stones all have at least three fabrics in them and there is one that has eleven pieces - in a two inch block. Stunning.