I would love to use it for remote blowers on vent hoods and downdrafts that have 3 speeds. I may check my supply house and put a roll on each truck if it's not too pricey. Also would be good for bath exhaust fans with a heater and light.
I use this stuff alot. Seems to be readily available. I ran into some old bx in a house recently that had the same setup red, black, white. white red stripe so I guess it is not a new idea. You can also get romex with black, red, blue, white. Works well for remote blowers.
I've used a couple times too. the first batch I got had two white wires in it and had to ring out and mark which was which. I guess it suppose to have black/white, red/white with red trace in order to pair them. 200.6(E) is a good point but it does have continuous white with a red trace, but I am sure someone will misconstrue somewhere down the line. But for right now it is nice to be able to get a 4 conductor RX.