I may not understand your question, but it sounds like you are going to do diagonal straight line quilting? I do a lot of straight line quilting, and quilt edge to edge whether vertical, horizontal or diagonal, and all the edges hold together. The spacing between your lines is the key, and be sure to follow the spacing instructions on the type of batting you are using. I usually quilt my straight lines 1" apart, which more than covers the batting requirements. Sorry if this doesn't answer your question.