I didn't test yet, but I did implement editing checkins so we can call this project complete. There was an API issue I had to patch, but other than that, implementing edit for checkins was smooth sailing.

One nice thing that isn't in the video is the segmented control at the top of the sheet works for toggling between the checkin's content and milestone.

There is a lot of issues with checkin rendering though, specifically around newlines. There's honestly a lot of issues everywhere. My work never ends.