this stuff isn't rocket science, i promise. if yer bow is bowyer rated for hmpe modern string fibers ("FF approved"), then use that fiber and don't look back! period.
flemish or endless build - pick one that makes you happiest, it doesn't matter one dang bit.
and NO, there is no "noise difference" 'tween the two string types. it's all in the design, the build, yer bow, yer arrows, and you the shooter.
most folks just don't understand about bowstrings and bowstring fibers, and strand counts. some folks will say that some bows, and shooters, work better together with a certain string fiber and build, and most of that is far more mental than reality.
chat with a trad gang string maker - any of these folks will help you get a good bowstring on yer g&l.