I did a similar thing to replace my personal workflow that I'd been using a home instance of JIRA for for some time.

I thought about opening it up, but TBH there's loads of these things already, and the real value for me is that I built it myself and it conforms perfectly to what I need. I looked at a few others, but the overhead of grokking someone else's tool was just too much of a hassle for me.

The ergonomics of these things are really close to perfect when you decide yourself what features you want and how they should be implemented.