Question: At this point, everyone knows that there's a limit to the number of `ShellIconOverlayIdentifiers` (from MSDN):

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> The number of different icon overlay handlers that the system can support is limited by the amount of space available for icon overlays in the system image list. There are currently fifteen slots allotted for icon overlays, some of which are reserved by the system. For this reason, icon overlay handlers should be implemented only if there are no satisfactory alternatives
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I can understand the 15 overlay limt in Windows 95. But in an environment where there's Gigs of RAM, numerous Cores, and GPUs, is there some technical reason for such a low number in a modern operating system?

And why isn't this value configurable?

*Before giving the 'performance' answer, consider:*
Windows allows for configuration such that you can kill performance... why pick on this issue specifically?

Answer: 
Excellent response on the practical issues by Cody. As to why 15 and not some other number, the limit is baked into the [ImageList](http://msdn.microsoft.com/en-us/library/bb775227.aspx) control itself.
This is all very well and good, as explained by Cody Gray, but frankly it is pretty unimaginative, and as reported behind the scenes, sounding a bit frustrated.

In 2015 and with Windows 10, surely there can and needs to be a better ability, as I noted about thirty overlays present and had to prioritize ones I wanted most to see, which is not what you want most people to worry about at all. Also I see aggressive vendors like Box over-competing to try to prioritize themselves, and that will never go any place good.

Here's a possibility: What if multiply overlaid icons had a generic overlay indicator; a small rectangle matrix of multiple colors like the Google Chrome Apps button? Singly overlaid would just show the overlay out of a long list.

Then when the mouse pointer meets the icon, a small flyout window collects all the icon variations to view (at small icon size or a little larger). Each overlaid icon in turn announces by tooltip what it is, when you mouse over.

Now you can have all the icon overlays you need, for state in various clouds, for repository indications as for Tortoise tools, and so forth.