I have an APQS Lucey which has a 26-inch neck. You definitely can use the stitch regulator to do ruler work. You need the thicker 1/4-inch rulers for ruler work. I like using my little 8-inch ruler the best as it is easy to hold and move but I have also used my 12 inch one. Longer than that, it just is too awkward to use. You will also need to get a ruler base which attaches to the machine and is used to support the ruler, so it does not tip.
gallery: mctavish quilting studio here are some examples of quilts Karen has done on her APQS