Different versions of same module in custom update center

I have also had this wish for many years. But thinking about it, I do not see it as a bad way to simply tell your end-user to use different URL's to the update.xml. Allowing numerous versions from the same folder would as I see it most likely open a can of worms and a lot of headaches with regards of controlling what users select to load into their app to maintain integrity of the code.   But - if anyone has some brilliant ideas I as well are interested to hear about it.