Is there a difference in noise for longbows using one vs the other?
Sometimes an endless can be a louder string but not always.Could be which string material it is made from.I usally twist up a Flemish for most of my longbows.I did spin up an endless loop for a Harrison HSS I had.I made it with Angel Majesty and a pair of cat whiskers and it was as quiet as my Flemish twist I made for it.
All else being equal, shouldn't be much if any difference.
I found that the ones that came with your Toelke (endless loop) are nice and plenty quiet, but I have become partial to Allen Schaffer's Ultra-cam and Fury strings, so I have a Fury on my Whip right now (flemish twist) and it is also a nice string.