The more I think about this I came to my own "conclusion" for myself to use the needle/thread combo that gives me the result I want. I like to try a lot of things - always open to an idea regardless of "I was always taught to...". There may be something new that gives a better result. So I have tried a lot of needle brands and sizes and types on my machines (all either vintage or mostly mechanical with an electronic one thrown in) which have no specific requirements of using "their" needles. And all kinds of threads including serger thread. So far I have had success that satisfies me. If something doesn't work I try something else. None of my machines are "persnickety".