As I see a bunch of comments on retakes, you might be interested in the discussions on a CC thread about CA doing away with D’s and F’s and replacing them with incompletes.
I’ve been studying a program called Grading for Equity by Joe Feldman for a doctoral program and wrote some detailed explanations of how it works in that thread. I also answered a lot of questions. Though I do have to warn you that, predictably, some of the posts went off the rails. But you can quickly recognize and ignore those. My first reply was the 5th on the thread and I continued to answer questions for a few days. Overall I was impressed with how genuine the discussions and questions were.