I've managed to get everything for Concentration working, except for the auto-save (notification). i.e. "Check for Save" option doesn't seem to do anything; no matter how much damage I deal to the concentrating character, no save - or mention of a save - is made. After some research, I thought maybe the '5th Edition OGL by Roll20 Companion" API script was required. But even after adding it, there doesn't seem to be any event handling of when a concentrating character's hp are reduced. Getting desperate, I starting trolling the code myself and discovered that all the concentration.autoRoll checks, beyond the setting and retrieving of the attribute's value, are disabled....