Something that requires less building and is still really cheap is building a foam insulation topper for your quilting table that custom fits your machine. I did this following Marguerita McManus' videos online tutorial and it has been the single greatest thing that changed my FMQ experience. My only regret is that I procrastinated so long before doing it. Perhaps if you had the tabletop level with your machine, you could still do the embroidery quilting on it without having to hold the quilt up. Either way, it would also make fmq much easier on your machine. I do all my quilting on my little 6.5in throat and having the machine level with the tabletop is crucial.
Video here:
https://youtu.be/g14govA4pIM
It's a 2 part video. Basically, you cut foam insulation (get it at Home Depot, I used the purple/pink Pink Panther one, because I couldn't find the blue thick one she used) to fit your machine. I taped mine together with packing tape, and then taped clear vinyl on top and covering the sides. She doesn't tape hers down I think, but I wanted the edges of the insulation covered so I did it and used packing tape to secure everything. It's held up well over about 4 years now so far.