Don’t forget with a floating foot to lower it before you start stitching. Because the foot floats above the fabric it is easy to forget to lower the presser foot- That will cause all kinds of bird nesting on the bottom because the tension disks arenkt engaged if the presser foot is not lowered.
another thing to remember is that with the floating foot , you need it to be just barely skimming the surface of the fabric, or just a tiny bit above the surface, otherwise you will get “flagging” (when the fabric gets brought up with the needle instead of staying down when the needle cones up out of it). Flagging will cause poor stitch formation and can lead to thread breakage.
the Janome convertible foot set which is the one you have that floats has a thumb screw on it whichyou can adjust to get the optimal height.
Rob