there is no such thing as a generalized "best string" for any bow. ditto for arrows, or most anything else. there is only what works well, or "best", for .... you, and not anyone else.
the fear of any bowyer is that the hmpe bowstring will not be built properly, padded in the loops, and that can easily be a problem for both bow and shooter. so, there is no reason to fear using hmpe bowstrings (ff, df'97, d10, 452, etc) on any stick bow that's built right in the limb tips. all current howard hill bows are fully capable of handling modern string fibers.
all my bows sport hmpe bowstrings because of their consistency in all conditions = low stretch and creep. since most hmpe (polyethylene) bowstrings are more than twice the breaking strength of dacron (polyester) bowstrings, low strand count bowstrings are quite feasible.
ymmv.