I was avoiding having any smarts in the server, just have it return a file, which could even be served from github. If we don't want a new release to be used we just don't put the number in the file. And that way you can modify the Mac version without any server support by PRing the file.
But I guess it depends on the infrastructure manager as to what smarts can be in the server and what they see as the best way for ongoing support.