Not sometimes. ALWAYS.
By the way, this needs to be fixed, or Avairian won’t be able to have his mod as he wants 
(unless he wants to touch the code files)
I’m going to change my mod and overriding the json files, as the tree variants arrays are simple (unlike the human customization variants) and will be able to have more variants. Nevertheless, modding the human variants with overriding of qb + variants in mixintos still has to be tested.