My mom always used Lipton onion soup mix in her stuffing - just followed the directions on the stuffing bag and added the soup mix to the water. The onions aren't crunchy at all but you get the depth of the flavor. I did it this way for years after I moved away from home, but over the years my taste has changed and it's now too salty for my taste.
Have you thought about adding some sage sausage (crumbled and browned) to the stuffing?
Also, if you sweat the onions and celery in a frying pan while you melt the butter, you can get them soft enough that they won't be crunchy. I'm not a fan of crunchy stuffing myself, so that's what I do - because I like the taste of the onions and celery.
