My understanding is the Grace Speed control does not work on the Jazz II. If you go to
https://graceframe.com/en/product/speed-control look under additional information tab and Jazz II is not listed.
There are many Jazz II quilters who use the Cutie frame that have attached the foot pedal to their handles with a bike
phone holder. Otherwise you have to purchase the Grace Elite regulator that is about $900 as the Grace Stitch Regulator will not work with the Jazz II either. If you are a Facebook user you might want to join the Cutie Quilters group or the group for Jazz II.