I had a well known (can't type in his name?) string builder build me a mixed material string a few years back.
I wanted an Ultracam/B50 combo string, and I wanted it that way to make the string quieter, and have better nock fit.
He warned/told me, that unless I was shooting fairly low draw weight as to not overload the strands of the B50, that it would not work as I expected it to, and tried to get me to let him just build me a good fastflight string.
Well, he was right. I was shooting 65#, and that mixed string made the bow crappy to shoot.
Luckily for me he sent an all ultracam string served for my nocks, and with silencers (for free mind you) along with the mixed string.
He sent a note along with the strings saying when I was convinced, to put the ultracam string on, and be happy, which I did, and was.
Pat