I finally found a little time to play with my cutter. I might have glued the magnets a bit too deep into the attachment because the first time I tried to use this, the head get pulled off the rods. I had to slow it down a lot (5 mm/sec) and had to change the height offset to about 0.25 mm so it would just cut the vinyl I had and not go through the vinyl backing. Still showed signs of torque on the head but since I slowed it down, it was able to stay together. Fun to do this, If I do use it, I'll have to redo the magnets so they are flush and have direct contact with the screws on the head, and/or re-do the 3d printed parts to provide more support. Great job regardless of my experience. Your millage may vary based on the vinyl used and how far out the blade is set, etc.
I also had some issues with FS (0.8.3) importing SVG files and then having it cut them. I used a simple square and when I used the 'duplicate' feature in FS, it made a copy, but didn't cut it. So, FS still needs some improvements.
I hope that the Flux development team can get the 3d printing to a point where they can re-focus and get some of the other features improved (like the cutting, scanning, engraving). for those that ordered your parts, have fun with this. It's great to see the creativity and ideas folks have in doing their own 'add-ons' to the Flux.