The issue is that if the check is performed server side, then the client needs to stop functioning if it fails. In other words, some of the functionality must be on a the server to leave the script non-functioning. When only a small piece of functionality is missing, developers can easily replace it. This means that a significant portion of functionality must be hosted on another server.
This is why I made RBXMod. In theory people can copy what it does for their own private service, but it is a lot of work. The value of RBXMod isn’t that it is making the impossible possible, but that it is saving developers from the work of setting up their own server with enough resources to support their games, handling communication and sockets, creating Lua instances read to and from files, saving persistent data, logins, purchases, ext. A single shared service.
So yes, someone can do this on their own server. However I don’t believe it will allow other developers to see the source of your scripts and trust them more. They must be missing a significant chunk of functionality.