I have been using two-sided 70D Ripstop nylon from Rockywoods Fabrics as a middle layer in accessory patches for tie points. It serves to increase the strength of the patch over a two layer patch.
I would not suggest it for a raft because the TPU coating peels off the nylon. The coating does not appear to be as well bonded to the fabric. I seem to recall the manufacturing of top-of-the-line TPU coated fabrics like DIY sells as requiring multiple rollings to impress the coating into the weave of the cloth. None of the samples I have received from Rockywoods, Seattle Fabrics came close to the much higher quality fabric DIY provides. Extrim Textil had interesting double coated and one sided fabric, but cost was European in scale and shipping unimaginable.