I.e Thaumcraft's brain would be a good example. Perhaps a config would be useful, too?

There is a bit of support in the form of a config added in v5.4.0. Currently, it will just cause the player's wendigo level to increase by a specified amount. I'll see about improving it on the next update.

This is long overdue, but the mod's development has been moved to another dev (https://github.com/MoriyaShiine/wendigoism).

Sorry, I didn't managed to get around in improving the config for body parts added by other mods.