Hi novapbs,
Yes there are certainly retailers that use them. You can see my comments about pressure mapping systems in post #4 here and post #2 here. They can tell you about your pressure points (which most people would already know) but they won’t tell you about your alignment on the mattress which is even more important. They can be somewhat helpful but I certainly wouldn’t rely on them and I would be very cautious if they are being used to recommend mainstream mattresses where you can’t find out the quality/durability of the materials in the mattresses they are “pointing to”.
Phoenix