So, your previous error report was due to the Unity Event action clip I just realized.
So, here is the fix for that part. Please open CutsceneInspector.cs and change method ‘TryCreateInspectedEditor’ about line #173, to be like this:
Noe regarding labeling clips, clips are automatically labeled to provide info as you have already seen. Raise Unity Event is a super rare exception where the information/label shown is indeed not that useful. I can see though that custom labels can come in handy in other action clips as well (?), thus I will add custom labels for the next version 🙂