Webdirect's homeurl parameter is currently a property of the host and not the file. It is buried in FileMaker Server's http config, and therefore it does not transfer with the file if the file is moved to a different host.
Instead, WebDirect's homeurl should be made a trivial and perhaps even dynamic property of each file, such that each file can have its own set of configurable actions that execute no matter what host the file is moved to.
For example, if WebDirect homeurl actions were to be included as options to the "Exit Applicaton" script step, it would make it possible to use different logic to dynamically specify the homeurl. Ideally, the script step could include the option to close browser tab/window, navigate to a different homeurl, or simply default to the standard WebDirect launch center.
If, on the other hand, homeurl properties were incorporated into the "Sharing --> Configure for FileMaker WebDirect" menu, then perhaps even there the homeurl could be specified via reference to a global variable, field, or calculation. Minimally, if homeurl must be hard coded, then at least the configuration would transfer with the file from host to host.