Custom iOS folder icons? Is it possible to create (or copy) custom icons to replace the composite folder icon made up of microscopic versions of the icons within said folder? Iconical does this nicely for apps but it doesn’t appear to have the means to customize folders’ icons. Is there an OS way or third party tool that allows for this?
I was thinking maybe a long way would be to make a shortcut which functioned like a folder but that seems clunky to set up and use. I’m hoping some smarty-pants has come up with a more elegant solution.
No, there isn't a way to do this with the stock iOS (any version).

The only way you can do this, and I've never tried it but I've read about it, is by jailbreaking the device first.  

You've already discovered the workaround which is to create a shortcut to an app that's within a folder. 

Until Apple allows this level of customization, you will not be able to change the looks of folders.