I have an HQ Simply Sixteen on the 5' Little Foot frame, and I also have the JUKI F600 sewing machine which is the same body as your F300. Imo, the F series machine would not work on the frame because of its small harp space, if for no other reason. The take-up pole requires space in the machine's harp, leaving you little, if any, room to quilt.
I don't know if there are carriages available to accommodate non-HQ machines for this frame.