No advantage to waxed linen at all there are many advantages to unwaxed, the main failure mechanism of stitch seems is loose stitching, Linen thread non-elastic zero extension holds the tightest knot, on the right-hand side of the solution box on the Pearson is two plates that nip together which is a thread break all machines with a thread break require a non-elastic zero extension thread to operate correctly, polyester elastic high extension won’t hold a knot, nylon highest elasticity highest extension will hold a knot but abrasive, service life, linen 2 centuries, polyester ten-year, nylon unfit for purpose. Comparing Linen to polyester and nylon is akin to comparing tool steel to knicker elastic and cheese strings. the first thread sewn into leather over thirty thousand years ago is Linen still the best by far.