If you really need HTTPS for debugging your app locally, you can use the Command Line Arguments and fill --SecurePort and the --Certificate path. You will have to use a valid certificate (or create a self-signed cert) and tell your computer to trust that certificate. Other than that, you should be able to do all this in the current Xojo release.
I might be missing something, but as far as I’m aware, there is anything I can fix in the framework in that sense. It’s a Safari policy that we cannot satisfy automatically 