I put a double nock on my straight limb bows and prefer to string bows that way, I use a para cord stringer.
My statics have too small of a tip to put an extra nock groove on. Normal leather cup bow stringers have too big of a cup to fit on my tiny static tips and can't be trimmed enough to fit properly and still stay on. I ordered a Bateman stringer for my granddaughter to use on her recurve and found to to be perfect on my tiny tip statics. It has a very small upper cup that is laced to tighten on your bow tip and not slip off.
Here is the size of my static tip;
Here is how the Bateman stringer fits on this tiny tip, plenty of room to get the string in the groove.