@Ledah and I were discussing this but it's my view (and possibly his) that the heat fed to Primordials are affecting them too much. It's causing most of them to end up with fire/stream and probably biasing the process too much.

Even creatures which haven't had anything "heat" related (as far as I have spoken to people) are getting fire shown on their primordials.

It's possible that future primodials heat should be removed, optional, or made to affect the system less?

Thoughts @Muratus del Mur ?

I've noticed the trend as well. On a side note, I have been, and will only be feeding my Primordial Heat. So if it's of any help, feel free to use my creature as the baseline for the most extreme influence Heat can become.