BREAKING BUG, DO NOT USE:
This addon seems to have broken something within the layer's instance ordering mechanisms, at least within more recent C3 versions.
More specifically, it has broken "move in front/behind object" actions, but not all the time.
I have no idea why this is the case at the moment, and will investigate. In the meantime, I'm marking this addon as deprecated as I don't want anyone else to run into the same issue I did. As long as this issue is not fixed, I recommend not using this addon and removing it from your projects if you do use it.