My DH zigzags everthing for me and I have no problems with fraying or tangles. He gets them done much faster than I do. He really makes my machine go. lol When I mentioned it, he asked if he was running it too fast and I assured him that the machine was made to move fast. I just don't have good control with a lot of speed. I'm more comfortable going slower.
I tried the laundry bag with fat quarters and had a mess with fraying threads wrapping the separate fabrics together so tight that I thought I would have to cut the fabrics to get them apart. I won't do that again. :)