Quilting large quilts with a 9" machine can be done but the quilt designs have to be adjusted or re-designed to do it with the limited space. You can stop, needle-down, and roll the quilt back & forth; some designs you can break in half and quilt it in 2 passes; you can do 5-6" passes up until the middle of the quilt--baste to the end--turn the quilt and start from the middle back toward the takeup roller; simple meanders, loops, puzzle pieces, stipples, etc. can be done easily--you just have to roll the quilt more often with the smaller machines. It is a pain but paying a longarmer is a pain in the wallet for simple quilting. Crawling around on the floor to tie or baste a quilt is a pain in the knees & back.
For me, hunching over my sitdown machine and pushing/pulling a bed size quilt was a pain in my shoulders & hands. Even a baby quilt, which I will still occasionally do on my domestic machine, hurts me but not as much now that I have the 9" domestic & it is set into the cabinet and I learned to put tables and books all around me to help support the weight. Where there is a will---there is a way!
For quilting on a frame, there is also I gizmo I used called a Max Throat which you might be able to find used. They don't make it anymore but I know there are still a bunch of them out there. It would roll the quilt back & forth on the take-up roller for you allowing you to get up to 16" in a single pass with a 9" machine. I loved mine but I will admit that it takes constant vigilance to make all the parts work together.
I have seen similar fabric/quilt advance gizmos but they have all been on the true long-arm machines. I'm sure there is some tinkerer that could figure out a similar idea to Max Throat for the home users.