The Cannibal perk's health restoration is a flat value, meaning at level 100 when the player has 700+ health, corpses will still heal you for only 50 health (at rank 3).There are many foods that heal more than that, and you don't need to make yourself vulnerable for 5 seconds to do it. Additionally, in Survival, 50 health isn't worth the Dark Craving disease, which makes it so you can't eat food to satiate hunger anymore.

Here's the gist of what this mod does:
Default Rank 1: Eat humans to restore 25 health.
Default Rank 2: Eat ghouls and super mutants to restore 25 health.
Default Rank 3: Humans, ghouls, and super mutants restore 50 health.

Modded Rank 1: While crouched, eat humans to restore 50 health (or satiate hunger), as well as send humans and non-feral ghouls running for their lives for 10 seconds.
Modded Rank 2: While crouched, eat ghouls and super mutants, and these plus humans restore 100 health (or satiate hunger).
Modded Rank 3: While crouched, humans, ghouls, and super mutants restore 200 health (or satiate hunger), and you immediately dispel the Dark Craving in Survival.

I say "immediately dispel" the Dark Craving because there's no way to remove the "You succumb to a Dark Craving" message without breaking perk functionality, so this wording makes more sense.

I also say "or satiate hunger" because in Survival, if the player is hungry, they get no healing benefits from food until their hunger is satiated. This includes corpses, which don't heal you unless you're not hungry. I've added this information to the perk's description so you don't forget.

Enjoy!