As you can see the FireFX is very broken same goes for campfire_fire but i got a solution thanks to @PeterA
In that pic i replicated what Peter suggested making two prefabs that use front and back of the firepit so there are two parts
then you spawn the BG part then the fire and at the end FG part where you use SetFinalOffset(0) onto the FireFX cause the fire will be still out of the firepit.
I recommend changing the symbols for the parts of the built firepit to "coldstones_fg" "coldstones_bg" depending on if its firepit or endothermic firepit.
Simply build Firepit or Endothermic Firepit