Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

Hello Billy  ....  yes, both of the functions you suggest are true for the most part. The heating elements will likely last longer operating at lower temperatures, and the water boils softer as well, so that you can control the engine speed to a certain degree, especially helpful on engines without steam line throttles.

Another alternative is a device marketed as a router speed control. They are good for up to about 15 amps / 1800 watts and are found from various sources at around the $20 mark. Harbor Freight sells them for a bit more than that, as seen here:

https://www.harborfreight.com/router-speed-control-43060.html

 

I just clicked on this hit for the router- speed- control. Laughed like crazy.    Click on it and scroll down to the reviews section, read the second one.
 Where the guy say's, to be honest I bought this for my wife. Read the whole thing.