I'm not sure where the idea of uncycled QT came from, but don't worry, I don't think you are the first to think this. QT is just that, quarantine, a place to observe new fish (or other critters) before adding them to the display tank. Given the fish will be in there a least a few weeks it needs a way to process/remove waste, that can be established bacteria or manual removal through water changes.
I keep a mesh bag of ceramic filter media in my sump at all times so I can setup a QT and have a fully cycled bio filter ready to go.
I keep a mesh bag of ceramic filter media in my sump at all times so I can setup a QT and have a fully cycled bio filter ready to go.