Definitely not enough stitching on your tie outs.
Strength is proportional to the length of your stitch lines whichever pattern you choose to go with, doesn't have to be a box, so adding another line of stitches would up the strength by around 50%
You may want to go with longer pieces of webbing to give more room for your stitching or alternatively use a zig zag to get enough stitches in.
Bookmarks