There should be an option for automatic playlist generation in Djay. You can export playlists explicitly, but why not make it an option to generate a log automatically?
Here’s my situation: using a first-generation Spin, if the USB cable is bumped (usually by a person leaning over my table to make a request), it can lock the Spin unit so the controls are non-responsive, even though the audio bus still works. 2nd worst case, I have to reboot the Macbook to get it to reestablish the device pairing. Worst case, occasionally bumping the cable will cause a kernel panic, but that is rare. When I lose mix control on the Spin, I switch over to my other deck attached to an iPad while rebooting to get the Spin back. Anyway, when I’m playing long sets, it would be great to see what I’ve already played after reboot.
Also, after the set is done, it would save my list in the event I forget to export.