Rape Tattoos groups

[Telis5678]

When it comes to setting up groups in the rape tattoos(continued) mod, I know it's all stored in that one JSON file, but you can also edit them in MCM. While editing in MCM, there are body groups as well as extra 12 groups(1a-d, 2a-d, 3a-d). Now my question is, are the body and extra groups specific name groups within the mod, that the mod specifically uses OR they are just groups based on them being the same name, so I could write however many groups I want directly into the JSON file and the mod will group the tattoos correctly as long as the group they're tied to is the same?

I don't see an easy way to check, hence why I'm asking here(the mod thread seems pretty dead).