Right now a user gets a request to provide the password when installation wizard starts up. If you install the service with a custom user account, it is not exactly trivial to access the file ("Run as Administrator"). It would be great to allow getting a temporary password from the installer.
Such feature likely requires Jenkins core patches to allow overriding the temporary password somehow. It might be also useful for other use-cases, so IMHO it is something to consider
I am not sure that Jenkins up to a point where the initial password is available. Generally, the service is started and then the installer exits. I can look into how it might be possible to wait for the file to be available.