Cursor Upgrade Carousel lets you easily access an item's upgrades or downgrades by shift+scrolling while holding the item:
You can also define your own custom upgrade paths. For example, the mod comes with a custom path that lets you easily switch between medium electric poles, big electric poles, and substations:
Please note that setting these custom upgrade paths does not effect upgrade planners - it simply lets you scroll those items as if they were upgrades of each other.
The mod is survival-friendly, as in it will respect the number of items you actually have in your inventory. If you do not have an item, the ghost cursor will be used instead.
Customization
The carousel is bound to whatever controls you have set for scrolling through blueprint books. If you wish to change this, here are the settings you must modify:
By default, when you are using the map editor, using the carousel will give you the items if you do not have them in your inventory. This can be disabled in the mod player settings.
Finally, vanilla Factorio defaults zooming to the mousewheel, and shift+mousewheel. It is recommended that you unbind zooming from shift+mousewheel so that your camera doesn't get spastic when you're scrolling through the carousel:
