Wow! Never knew this was a thing. Would that be enough to power heavier load appliances (toaster ovens, window AC, etc)?

it's at that state now, yes. 100W PoE is standardized and available on the market. the standards body dragged their feet for a couple decades, vendors implemented their own proprietary high-power PoE injectors and devices, and a lot of the momentum behind PoE died out due to incompatibility hell. imagine every power outlet in your house was networked, could support gigabit data transfer, and the whole thing was so safe you could jam a fork into the outlet whenever the whim struck you -- that was the original dream.