Unless I can test the strength of the thread myself, I wouldn't risk it. Many years ago, I was told that serger thread was acceptable for piecing and quilting. After a few years, I realized that my queen sized quilt was popping threads everywhere creating toe catchers. What a waste of time and money that was. I was also given some thread that was so old that it broke easily. I now purchase only quality thread. I look for sales from Superior thread, Aurifil (from Craftsy), Connecting Threads, and occasionally Gutermann.