Thought I would share my findings after hand sewing appliqué this week. I used aurifil 50wt thread with both Thread Magic and then Sew Fine Thread Gloss.
Sew Fine was a recent purchase I made after seeing it promoted elsewhere - it certainly “coated” my thread but I felt a distinct drag when pulling through the fabric layers. No fraying, no tangles but did not allow my thread to move through the fabric smoothly. Back of the small can says ingredients are beeswax, coconut oil & fragrance. BTW - it smells great!
Thread Magic is a product I’ve used for a few years and by comparison works better - for me - nice & smooth movement, no tangles or issues of any kind. The brand does not seem to share its ingredients.
Lastly, I plan to try polyester thread with no conditioner at all and am anxious to see how that feels and looks compared to what I’ve always done.