The current nethack-vultures uses a very old version of nethack. It is bundled because a customized version is used to support the isometric view. There exists source for a slight more recent version, but it is still very old. The upstream web site is now dead and they weren't very good about publishing source. So I can't get code from just a few years ago. At this point, I don't think it is worth the work to support this different UI for nethack.
If someone else wants to take it over, I'm fine with that. The latest version I was able to find was 3.67. I don't seem to have a copy of that, but old Debian releases probably have it. When I last looked at it, going from the current Fedora version to 3.67 was a substantial amount of work. The current version is crashing on start up, so even keeping the status quo needs some work.