I understand your concern. I have a toddler in the house and was worried about it as well when I started.
But only palys produce it and use it as a defense mechanism. It resides within the tissue of the coral.
I recall the tidal gardens spotlight on Zoas stating that zoas can contain paly toxin, but that it was unclear if they produce it or absorb it.
It’s up to you, to weigh the risk versus the reward. Zoas are gorgeous corals. And present the most risk when trying to propagate or frag the coral. Or when atttempting to remove them from your rocks(usually people removing palythoa)
Personally, I think most palys are ugly by comparison anyways. And won’t be adding them intentionally because they definitely contain the toxin. I do have Zoas and am adding more soon.
If you have a family or roommates it may be worth mentioning to others that this potential exists.
It is a very rare thing, But I believe in Murphy’s law and so take all precautions you can if you choose to frag palys or Zoas. Even though only some Zoas contain it, nobody says which ones do and do not. As stated by others PPE is a great idea, mask, goggles, gloves and possibly a face splash shield.