Here's what's happening, imho. You cannot change string MATL and have same poi, no matter the brace height. As far as I know, there are currently 4 strings available. Two are Flemish, two are endless loop dacron. The Excel green and brown threads on mine come close to interchanging w/ the green and black Flemish dacron. The black endless loop is called the standard, don't shoot it, so don't know about it. The last is FFF, grey and black Flemish, which is the fastest. So, to reiterate, you can switch back and forth between the Excel and Flem dacron, but believe the rest require sight adjustments. For me, going from Excel to FFF is two clicks on V-zone at 20 yds. You might want to go to Excals site under accessories and look at them, but if I recall, they only show three.