Do you think the symbol art for crochet stitches had made an improvement in doing patterns [ doilies ] faster?

Yes, it is so much easier than trying to keep track of every row. Have you tried the doilies in the "Nihon Vogue" pattern books? They are all done that way. I first saw them at my public library and liked them so much. I ordered my own copies from Chapters book store. I've even evolved to the point now where I do part of one pattern and part of another in the same doily.