My wife has done FMQ on several quilts using her Singer 401A. It was the machine that she used when she began learning how to FMQ. She has done it both with the needle plate up and the plate down, and didn’t notice much difference one way or the other. She set her stitch length on zero, used a darning foot, size 11 needle, Maxi-Lock serger thread (Tex27), and used her straight stitch needle plate. The machine was mounted in a Singer 430 Profile 3-way Sewing Desk (43 1/4" x 37 1/2" working surface), so she had plenty of room and support. She had good luck with it.
Then I set her up a Singer 96-40 industrial (20"x48" top), but it gave her fits. I had the feed dogs removed and a solid needle plate (no feed dog slots) on it, but I was slow in getting her a good darning foot for it. She broke a couple of cheap cheesy ones that I had rigged up. It was mounted in a treadle stand with a small electric motor for temporary power, and the treadle plate was in her way to get into a comfortable position to use her electric foot control. By the time I got a good darning foot for it, she had moved on to my Singer 301A mounted in the large cabinet that her 401A had been in, and she likes it best. I’m planning on setting the 96-40 up as a treadle sometime to see how she gets along with it that way. She didn’t want to treadle while she’d learned to FMQ, and I just haven’t gotten it set back up again for her.
CD in Oklahoma