Interesting. I have a minor change to the Channel mode UI that I keep on a branch and rebase to master frequently - it adds the RX frequency and TX offset if any to the very bottom of the display. I tried to get it merged, but Roger didn't see enough interest in it at the time, so the pull request got closed.
It seems very important to me to see the frequency I'm receiving, and the frequency I'd be transmitting on. Daniel added a feature that shows the frequencies when you press SK1 in channel mode, but I still like to see the frequency while I'm browsing channels, so I'm still maintaining my branch.
Very importantly you can't do that with the stock firmware. Well, you sorta can the way folks do for the MD-380 but that's a lot less accessible to folks like me who only dabble in C. But having an open source firmware for a radio, with great maintainers, is a game changer for me. If I want my radio to work a little differently I can do that and that's awesome.
I wonder how many other changes there are out there that folks are maintaining for themselves.