JanTx ... your work looks really great
The Janome 6600 is a great machine. Til I had it, I had no use for FMQ, as it just didn't seem to click for me. What made the difference for me was ... the blue dot bobbin case as well as the FMQ special packet of three interchangeable feet. I really liked the clear plastic foot. With these, I seldom had problems with the back threads.
You didn't mention whether you have these or not ..... so I thought I would suggest them to you.
Another suggestion for all ... when you are changing things to get it right, only make one change at a time. If you make more, you have no idea what works, or what doesn't. Trying different variables can be time consuming, but at least you know.
Though, with the above extra accessories, it took very little effort to get my machine set up whenever I wanted to FMQ.