I have the exact thermostat and it does cycle my electric furnace at 40 degrees. Mine is a couple years old and I also fine tuned the operation by tilting.
Yes, 2 nuts is the correct method. I have the original installation manual and that is the methos pictured. The cable side is the follower and the lock does not engage during normal operation.
My lift suffered a cable failure 2 years ago while in use as an alignment rack with a vehicle...
Let me be the proud Papa here.
My avatar shows my youngest son on the left, son-in-law in middle, me on right all watching Mightymg (oldest son) working on a Land Rover.
It's good to be proud.
I'm "all in" with the new program. Ben to, and left, many forums in the past that got out of hand.
BUT, I do love a good flame thread...in the right spirit.