Yeah, BCYX is low stretch, Not suitable for older wood bows. I shoot a combination of carbon limbs and have not had a problem.
I think it’s worth noting that there are other factors Related to limb stress. I shoot a fairly heavy hunting Arrow which puts less stress on the limbs. All of the problems we used to see with those old Oneida compounds was guys shooting very light arrows which left a lot of excess vibration and energy in the bow itself.
I think the same thing happens with Single string bows.
it’s worth mentioning that when I build my skinny strings, iPad the loops and I also beef up the serving so my noks fit. I sometimes mix in two strands of some 452 that I have in black along with the brown BCYX so that I can see the twists.
I’ve been using that material in my own strings for at least a few years on multiple bows even down to a 40 pound set up with a 380 green arrow and no problems