That whole thing about poly cutting the fabric is really a myth. If you look at the Superior Threads Web site ( as mentioned earlier) they have some great thread education videos.
I have been using poly or blends for decades, no cutting of the fabric. I was thrilled when Superior Threads had a learning video that supported what I already know to be true in my own experiences. Poly or blends are much less linty! What matters the most the quality of the thread and not all blends or 100 percent cotton are of the same quality. There really is quite a bit that goes into a quality thread , the lenght of the fibers, the twist on the fibers, how many strands are used etc.