I want to know what is being used "in coding" to determine what the next fungal shift will be.

I know the seed can be used to "decode" information about the game but;
Is there any way to check exactly what the next shift will be, with mods that add things outside of the seed's code (liquid/gases and potion mods), or is the seed mandatory for finding out what mixes with what, or what fungal shifts into what.