I have asked for something similar in other forums. My background is in AutoCad where we would put a TAG block on every door, window, cabinet, etc. A TAG could be a data list of as many details as you want and you can show or hide whichever details you choose. You can copy and paste a TAG to duplicate instances of components. Then build a parts list from all the TAGs that updates when you add or subtract them.
So it seems like this could easily be done with the information in SketchUp components. I would think that the #ofInstances count would be built into a parts list function, (or components list), built into Layout. I wouldn’t want to add each number to into the attributes of each component.
I have never used cutting list extensions in SketchUp. Do any of them cover this functionality?