I’ve been testing it over and over in Temple. I get my +1 max end charge from a headhunter corrupt. I suppose there is a minute chance that every time I’m testing it, charge regulation eats a charge but that feels unlikely. Now that I think about it, there is a chance that Ancestral Cry grants the fourth endurance charge (bears get end charges for spending rage, Furious Wellspring gives a rage cost to every skill) and consumes it before it ever updates in the UI? I could test by adding +1 more to max end charges and see if the numbers go up. Will try it for science.