The statement below is false.
The statement above is correct.
Re: Yellow sign 1B (to easy for the keeper)
It is not once per turn. The card does not say that.
That is the problem. You can place that much mutation tokens as you have threat in single turn on one investigator
You didn't post the card text in this thread and I don't have the game with me, so I went with the card text you posted in another thread:
Keeper Action card - Unwilling Test Subjects
Action: Once per turn, you may either
Discard 1 mutation token from a monster to heal 2 damage from another monster in its space,
Give an investigator in the same space as a Cultist 1 mutation token.
Is that text incorrect then? Because that clearly says "once per turn"