The designer did not listen to my instructions.
I told the salesman that the floor was highly insulated below the subfloor and that the vinyl covering had a temperature limit of 85 degrees. He specified your hottest possible arrangement for the floor size. (Three inch spacing with 3.7 watt wire and very narrow areas at the edge.) It should have had 4 or 5 inch spacing with your cooler 3.0 watt wire. ) I did not catch it until I had it for a while and was very bothered that it was too hot. Eventually I had to send it back and order a much shorter wire.