I think the risks of lowering the tire pressure may be being a bit overblown. I am not arguing that lower tire pressure does not increase the heat build up in the tires, but what we are describing here is well within the limits the tires can sustain, which is supported by the anecdotal evidence that we are not hearing of a rash of side wall failures. Personally I have never had a blow out, even after thousands of miles of reduced tire pressure.
The key thing here is that tires are rated for a certain pressure at a certain speed, so you can reduce the tire pressure or increase the speed, but not both. In my case (LT 235/85R16 E 120/116S) the tires are rated for 112MPH. On the highway I run 50/55psi and drive up to 80 Mph, well within the manufacturers limits of the tires. If I air down to 35psi, based on the load tables I am actually still within specification, however at 30psi I am just out of specification. Now the most important factor is that at reduced pressure I won't drive more than 40-45Mph, so ~1/2 my highway speed and ~1/3 the rated speed of the tire.
By watching the TPMS pressure readout you can infer tire pressure - on the highway at 75mph I see about a 5psi increase in tire pressure, which indicates about a 30C increase in temperature. When aired down I watch this carefully and typically see 1-2psi between cold and hot pressure, which is about a 25C increase in tire temperature - not something to be worried about. Again, the key here is the speeds are half as fast or slower so there is actually less heat build up in the tires.