Perhaps a few drops (or a vertical line) of the silicone type lubricant which I believe is called Sewer's Aid on your thread might help. It may give a touch of lubrication to your upper tension and ease the passage of the thread. I love using a 90 topstitch needle for most of my sewing. I do not have LA or midarm so do not speak from experience on one...only garment sewing and piecing and FMQ on my DM. Good Luck, I truly understand your frustration...I'll say a prayer for your peace of mind.