Room temperature SS has a known resistance. As the temperature increases so does the resistance (slightly) in a predictable curve. This property is the basis for metals use in TC devices.
The reason (as I understand) why SS can be used in non TC devices is that range of change in resistance is sufficiently small that it can be used without TC regulation without issue. I may be wrong so someone please correct me if I am.
I like using SS in mechs because compared to kanthal it has a much lower resistance for a given mass of wire. So for a given resistance you can benefit from more surface area.