The currently installed "zsync" only supports standard http URLs but there was a version available called "zsync_curl" that did support transfers over https. Alas it wouldn't install on Elive Beta until now.
I have altered the existing "zsync_curl" package that was available on github but had an incompatibility with Buster and thus with Elive Beta by removing a "libcurl3" dependency....which wasn't any good anyway.
- It works fine over https using the command "zsync_curl" from the commandline (sorry @Rebel450 haven't had time for a GUI ) :
Thus minimizing download data, as well as workload on the server.
The installable .deb package can be downloaded here: