Left 4 zed vs mutagen

Uhh i noticed that Left 4 zed didnt do anyting compared to unstable mutagen is this a bug or am i missing something?

I haven’t played botany in ages, so I’m completely out of the loop of the new(ish) stuff. Looking at the code, they do seem different.

Unstable Mutagen:
  - !type:PlantAdjustMutationLevel
    amount: 1

Left 4 Zed:
    - !type:PlantAdjustNutrition
      amount: 1
    - !type:PlantAdjustHealth
      amount: -0.5
    - !type:PlantAdjustMutationMod
      prob: 0.3
      amount: 0.2

So UM increases the mutation LEVEL, while L4Z increases nutrition, decreases health, and possibly increases mutation MOD. Reading other parts of the code, it seems that the MODifier does nothing by itself, but it makes increasing the LEVEL more effective.