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 ) :
but where is the git repository from where I can get the sources to compile and thus making a package from it? i dont remember what i did but i was unable to do it when i looked at it
Ah, funny that rebuilding an existing .deb with only the libcurl3 dependency removed worked fine on my machine.Wonder if that had been seen to there.
Anyway, it's working now from repo so that's good.