I believe you can make a good spot better with additional cover. Adding cover in an area where you haven't caught fish is always a dice roll. I've caught fish for 25 years around the same PVC I dropped in a private lake in Texas. It's in about 10 feet of water and I can catch Crappie around it year round. I've also dropped brush that I've never been able to catch a fish around.
I'm sure I'll die in my 80's and still know very little about Crappie