!!!BE CAREFUL!!!

Yeah, man... it doesn't work well.
I started as a zombie, there was no way to die. I used godmode to be able to die, become a human, and then die. I removed the game from the server and only a few days later realized I was intangible to zombies, even without the mod installed.
After that, I tried countless ways to remove my immunity, but nothing worked.
No solutions on the horizon other than starting a new server, because I'm the Highlander now thanks to this mod.
Spoiler: Immortality sucks.
Given that the issue has been reported for almost two years and there's no response, my recommendation:
DO NOT USE THIS MOD, AS IT MAY PERMANENTLY DAMAGE YOUR SAVE AND, APPARENTLY, NOTHING IS BEING DONE ABOUT IT.

Related: Immortality, stuck in godmode, invulnerable to zombies, zombies don't attack you, zombies don't bite you, Zomboid Hilander mode.