If I may chime in...I recently tried an adapter called the "Thread Director"...and by golly, it helped me tremendously. All my Sulky metallic threads are now actually usable, which is a shock....as long as I go slowly, keep to simple stitches, and use a really large eyed top stitch needle...I think its a 90. And I lower the tension a little too.
I have even been able to use some of the Sulky "Holoshimmer" spools that I had completely given up on. For some reason, the red Holoshimmer will still absolutely NOT work on my machine, but several other colors will.