Welcome to the Quilting Board!

Thank you for posting this, I would love to try using a ruler for quilting
The biggest risk is the one not taken
I just did this today. I made a pot holder.
I clipped two 6" X 1" Omnigrid rulers together with small bull clips (if that didn't work for me I planned on using tape.).
My first attempt at using the darning foot wasn't very good so I tried it with a regular straight-stitch foot on my 403A but regardless of how light I set the presser foot pressure I continued to get distortion of the fabric (probably due to the bias grain on certain sides of the triangle). I didn't have a slant zipper foot in my arsenal so I returned to using a darning foot and just decided I'd have to learn how to move the fabric and ruler together to get a good free motion stitch lengths.
It was fun. I'll do it again but make my triangles bigger and use 1/2" rather than 1/4" increments. I found that the quilting was too dense even for a potholder by using 2" triangles and the 1/4" increments.
Thank you for the link yngldy.
The video said to have the machine set-up for free motion quilting which usually means to have the feed dogs dog and the stitch length at zero. It appeared to me that she was doing regular stitching and the machine controlled the length and the quilter the direction by turning the fabric. Am I wrong?
I wonder if you put tape over the feed dogs if you would still have the tension but would be able to move the piece however you needed. Just a thought. I have that zipper foot and yes, it is a Viking zipper foot.