RE: STS ?
I have an STS system on my Old Glory and I did not add serving to my string. I originally tried the STS on my Allegiance and didn't add serving to the string and never noticed any extra string wear so I didn't add it to my OG. The STS is a great tool but it can be a little tricky to set-up and tune with, when that is all done it is one of the best add-ons you can make in my opinion!