The classification system is for the entities that comprise a device and is determined by the device’s integration. Users have no control over an entity’s category.
What you’re requesting would be fulfilled by a feature that has been outlined (by Frenck) but, as yet, unimplemented. The user would be able to assign one or more ‘labels’ to an entity. The label’s name can be whatever you want. Afterwards, you can select/organize entities by their labels.
I hope to see Labels one day! Would Labels enable hiding entities from the Overview dashboard though? I guess we don’t know as they don’t exist or aren’t finished.
I suppose being able to make virtual devices to hold multiple Helper entities would be nice but, that’s a different feature request.