I just installed systemd on my Debian system. Version is 44. I was looking at the numbers in systemd-analyze and noticed that networking.service was taking, for some reason, 15s to start, blocking a good chunk of the boot with it. So I restarted to see if I could reproduce without rebooting entirely, and it turned out I couldn't. But then the networking.service timing disappeared completely from systemd-analyze plot, and only the new duration was shown in systemd-analyze blame. It kind of makes sense for blame (though it could be argued), but it kind of defeats plot's purpose.