The springs are optional, really. You can use them or not, you can use 1 or both. It depends on how heavy your EP's are, and whether you want to use some other counterweight system on the front or back of the scope.
I use 1 spring some of the time, no springs most of the time.. until I have my 14mm UWA in, and then I use a weight on the back as well as 1 spring
Congrats on a great purchase! A lifetime of love.